Numerous epidemiological studies and comprehensive reviews of the scientific literature have evaluated possible associations between exposure to non-ionizing EMFs and risk of cancer in children. (Magnetic fields are the component of non-ionizing EMFs that are usually studied in relation to their possible health effects.) Most of the research has focused on leukemia and brain tumors, the two most common cancers in children. Studies have examined associations of these cancers with living near power lines, with magnetic fields in the home, and with exposure of parents to high levels of magnetic fields in the workplace. No consistent evidence for an association between any source of non-ionizing EMF and cancer has been found.
Exposure from power lines. Although a study in 1979 pointed to a possible association between living near electric power lines and childhood leukemia, more recent studies have had mixed findings. Most of these studies did not find an association or found one only for those children who lived in homes with very high levels of magnetic fields, which are present in few residences.
Several studies have analyzed the combined data from multiple studies of power line exposure and childhood leukemia:
- A pooled analysis of nine studies reported a twofold increase in risk of childhood leukemia among children with exposures of 0.4 μT or higher. Less than 1 percent of the children in the studies experienced this level of exposure.
- A meta-analysisof 15 studies observed a 1.7-fold increase in childhood leukemia among children with exposures of 0.3 μT or higher. A little more than 3 percent of children in the studies experienced this level of exposure.
- More recently, a pooled analysis of seven studies published after 2000 reported a 1.4-fold increase in childhood leukemia among children with exposures of 0.3 μT or higher. However, less than one half of 1 percent of the children in the studies experienced this level of exposure.
For the two pooled studies and the meta-analysis, the number of highly exposed children was too small to provide stable estimates of the dose–response relationship. This means that the findings could be interpreted to reflect linear increases in risk, a threshold effect at 0.3 or 0.4 μT, or no significant increase.
The interpretation of the finding of increased childhood leukemia risk among children with the highest exposures (at least 0.3 μT) is unclear.
Exposure from electrical appliances. Another way that children can be exposed to magnetic fields is from household electrical appliances. Although magnetic fields near many electrical appliances are higher than those near power lines, appliances contribute less to a person’s total exposure to magnetic fields because most appliances are used for only short periods of time. And moving even a short distance from most electrical appliances reduces exposure dramatically. Again, studies have not found consistent evidence for an association between the use of household electrical appliances and risk of childhood leukemia.
Exposure to Wi-Fi. In view of the widespread use of Wi-Fi in schools, the UK Health Protection Agency (now part of Public Health England) has conducted the largest and most comprehensive measurement studies to assess exposures of children to radiofrequency electromagnetic fields from wireless computer networks. This agency concluded that radiofrequency exposures were well below recommended maximum levels and that there was “no reason why Wi-Fi should not continue to be used in schools and in other places”.
A review of the published literature concluded that the few high-quality studies to date provide no evidence of biological effects from Wi-Fi exposures.
Exposure to cell phone base stations. Few studies have examined cancer risk in children living close to cell phone base stations or radio or television transmitters. None of the studies that estimated exposures on an individual level found an increased risk of pediatric tumors.
Parental exposure and risk in offspring. Several studies have examined possible associations between maternal or paternal exposure to high levels of magnetic fields before conception and/or during pregnancy and the risk of cancer in their future children. The results to date have been inconsistent. This question requires further evaluation.
Exposure and cancer survival. A few studies have investigated whether magnetic field exposure is associated with prognosis or survival of children with leukemia. Several small retrospective studies of this question have yielded inconsistent results. An analysis that combined prospective data for more than 3,000 children with acute lymphoid leukemia from eight countries showed that ELF magnetic field exposure was not associated with their survival or risk of relapse.
Power lines and electrical appliances that emit non-ionizing EMFs are present everywhere in homes and workplaces. For example, wireless local networks are nearly always “on” and are increasingly commonplace in homes, schools, and many public places.
No mechanism by which ELF-EMFs or radiofrequency radiation could cause cancer has been identified. Unlike high-energy (ionizing) radiation, EMFs in the non-ionizing part of the electromagnetic spectrum cannot damage DNA or cells directly. Some scientists have speculated that ELF-EMFs could cause cancer through other mechanisms, such as by reducing levels of the hormone melatonin. There is some evidence that melatonin may suppress the development of certain tumors.
Studies of animals have not provided any indications that exposure to ELF-EMFs is associated with cancer. The few high-quality studies in animals have provided no evidence that Wi-Fi is harmful to health.
Although there is no known mechanism by which non-ionizing EMFs could damage DNA and cause cancer, even a small increase in risk would be of clinical importance given how widespread exposure to these fields is.
News coverage of an issue as controversial and complex as EMF health effects is more likely to reflect the views of whichever interest group has been the most successful at capturing the attention (or securing the support) of the media. Journalists are, for the most part, generalists who are required to cover a wide range of issues, and who often lack the background to understand the information in a press release. This makes them vulnerable to the influence of any “specialists” to whom they turn for assistance. If you are really interested in something, find and read the press release of the organization who performed the work or issued the report.
As for what you find on the Internet…., be sure to read multiple sources. Beware of sites which prey upon your fears, or encourage adversarial actions. Misinformation is rampant. Also watch out for EMF mail lists and newsgroups populated by pseudo-experts who are all too eager to dispense questionable advice. Generally, .gov and .edu sites are the most reliable.
There are both natural and human-made sources of non-ionizing EMFs. The earth’s magnetic field, which causes the needle on a compass to point North, is one example of a naturally occurring EMF.
Human-made EMFs fall into both the ELF and radiofrequency categories of non-ionizing part of the electromagnetic spectrum. These EMFs can come from a number of sources.
Extremely low frequency EMFs (ELF-EMFs). Sources of ELF-EMFs include power lines, electrical wiring, and electrical appliances such as shavers, hair dryers, and electric blankets.
Radiofrequency radiation. The most common sources of radiofrequency radiation are wireless telecommunication devices and equipment, including cell phones, smart meters, and portable wireless devices, such as tablets and laptop computers. In the United States, cell phones currently operate in a frequency range of about 1.8 to 2.2 GHz. (For more information about cell phones, see the NCI fact sheet Cell Phones and Cancer Risk.) https://www.cancer.gov/about-cancer/causes-prevention/risk/radiation/cell-phones-fact-sheet
Other common sources of radiofrequency radiation include:
- Radio and television signals. AM/FM radios and older VHF/UHF televisions operate at lower radiofrequencies than cell phones. Radio signals are AM (amplitude-modulated) or FM (frequency-modulated). AM radio is used for broadcasting over very long distances, whereas FM radio covers more localized areas. AM signals are transmitted from large arrays of antennas that are placed at high elevation on sites that are off limits to the general public because exposures close to the source can be high. Maintenance workers could receive substantial radiofrequency exposures from AM radio antennas, but the general public would not. FM radio antennas and TV broadcasting antennas, which are much smaller than AM antennas, are generally mounted at the top of high towers. Radiofrequency exposures near the base of these towers are below guideline limits, so exposure of the general population is very low. Sometimes small local radio and TV antennas are mounted on the top of a building; access to the roof of such buildings is usually controlled.
- Radar, satellite stations, magnetic resonance imaging (MRI) devices, and industrial equipment. These operate at somewhat higher radiofrequencies than cell phones.
- Microwave ovens used in homes, which also operate at somewhat higher radiofrequencies than cell phones. Microwave ovens are manufactured with effective shielding that has reduced the leakage of radiofrequency radiation from these appliances to barely detectable levels.
- Cordless telephones, which can operate on analogue or DECT (Digital Enhanced Cordless Telecommunications) technology and typically emit radiofrequencies similar to those of cell phones. However, because cordless phones have a limited range and require a nearby base, their signal strengths are generally much lower than those of cell phones.
- Cell phone base stations. Antenna towers or base stations, including those for mobile phone networks and for broadcasting for radio and for television, emit various types of radiofrequency energy. Because the majority of individuals in the general population are exposed only intermittently to base stations and broadcast antennas, it is difficult to estimate exposures for a population. The strength of these exposures varies based on the population density of the region, the average distance from the source, and the time of day or the day of the week (lower exposures on the weekends or at night). In general, exposures decrease with increasing distance from the source. Exposures among maintenance workers have been found to vary depending on their tasks, the type of antenna, and the location of the worker in relation to the source. Cumulative exposures of such workers are very difficult to estimate.
- Televisions and computer screens produce electric and magnetic fields at various frequencies, as well as static electric fields. The liquid crystal displays found in some laptop and desktop computers do not produce substantial electric or magnetic fields. Modern computers have conductive screens that reduce static fields produced by the screen to normal background levels.
- Wireless local area networks, commonly known as Wi-Fi. These are specific types of wireless networking systems and an increasingly common source of radiofrequency radiation. Wireless networks use radio waves to connect Wi-Fi–enabled devices to an access point that is connected to the internet, either physically or through some form of data connection. Most Wi-Fi devices operate at radiofrequencies that are broadly similar to cell phones, typically 2.4 to 2.5 GHz, although in recent years Wi-Fi devices that operate at somewhat higher frequencies (5, 5.3, or 5.8 GHz) have appeared. Radiofrequency radiation exposure from Wi-Fi devices is considerably lower than that from cell phones. Both sources emit levels of radiofrequency radiation that are far below the guideline of 10 W/m2 as specified by the International Commission on Non-Ionizing Radiation Protection.
- Digital electric and gas meters, also known as “smart meters.” These devices, which operate at about the same radiofrequencies as cell phones, transmit information on consumption of electricity or gas to utility companies. Smart meters produce very low-level fields that sometimes cannot be distinguished from the total background radiofrequency radiation levels inside a home.
For household appliances and other devices used in the home that require electricity, magnetic field levels are highest near the source of the field and decrease rapidly the farther away the user is from the source. Magnetic fields drop precipitously at a distance of about 1 foot from most appliances. For computer screens, at a distance of 12–20 inches from the screen that most persons using computers sit, magnetic fields are similarly dramatically lower.
EMF meters or Gauss meters measure magnetic fields in mG (milligauss) or μT (microteslas [millionths of a Tesla]) and electric fields in V/m (volts per meter). These are simply units of measure, like an inch or a pound.
If transformers are in vaults or sequestered ‘electric rooms’ associated with large commercial buildings, or on the other side of a wall in a commercial building, extremely high fields can be created in occupied areas adjacent to these units. The same applies to other components of the electrical system connected to the transformers.
In regard to transformers on poles and transformers on the ground in residential neighborhoods, probably not. The magnetic field is very high close to these units, but drops off rapidly as one moves away. At as little as 4 to 5 feet distance the field is usually down to background levels, and people are seldom that close for a significant period of time. On the other hand, the wires feeding into and out of the transformer produce fields that may not drop off as quickly. The real question is: How close are these wires (underground or overhead) and how high is their field?
Any type of line can be a problem if it has enough current flowing through it and it is close enough. Distance is the most significant and effective mitigator of the field strength.
Even though large transmission lines elicit the most concern, more people actually experience elevated fields from overhead distribution lines that run through neighborhoods and down city streets, or from underground residential distribution lines (URD lines). That’s because these lines are often so close that the field, however limited, sometimes impinges upon living or working areas. Also, distribution lines are usually operating with some degree of net imbalance, which causes the magnetic field to drop off more slowly with distance.
At power line frequencies, electric and magnetic fields exist as separate forces with unique properties, but they are collectively referred to as electromagnetic fields.
An electric field is present wherever electricity is present, even though no current is flowing (no electricity is in use). Its strength is proportional to the voltage of the electrical supply, and is measured in volts per meter. An electric field is blocked or substantially reduced by intervening structures, including trees and most common building materials.
A magnetic field is present only when electric current is actively flowing (electricity is in use). Its strength is proportional to the amount of current flowing, and is measured in a number of different units, of which milligauss is the most common in the United States. A magnetic field is not substantially reduced by most materials.
The magnetic field is the component most closely identified with the potential for adverse bioeffects, and is also the component responsible for equipment interference problems.
Electric and magnetic fields are invisible areas of energy (also called radiation) that are produced by electricity, which is the movement of electrons, or current, through a wire.
An electric field is produced by voltage, which is the pressure used to push the electrons through the wire, much like water being pushed through a pipe. As the voltage increases, the electric field increases in strength. Electric fields are measured in volts per meter (V/m).
A magnetic field results from the flow of current through wires or electrical devices and increases in strength as the current increases. The strength of a magnetic field decreases rapidly with increasing distance from its source. Magnetic fields are measured in microteslas (μT, or millionths of a tesla). One microtesla =10 milligauss.
Electric fields are produced whether or not a device is turned on, whereas magnetic fields are produced only when current is flowing, which usually requires a device to be turned on. Power lines produce magnetic fields continuously because current is always flowing through them. Electric fields are easily shielded or weakened by walls and other objects, whereas magnetic fields can pass through buildings, living things, and most other materials.
Electric and magnetic fields together are referred to as electromagnetic fields, or EMFs. The electric and magnetic forces in EMFs are caused by electromagnetic radiation. There are two main categories of EMFs:
- Higher-frequency EMFs, which include x-raysand gamma rays. These EMFs are in the ionizing radiation part of the electromagnetic spectrum and can damage DNA or cells directly.
- Low- to mid-frequency EMFs, which include static fields (electric or magnetic fields that do not vary with time), magnetic fields from electric power lines and appliances, radio waves, microwaves, infrared radiation, and visible light. These EMFs are in the non-ionizing radiation part of the electromagnetic spectrum and are not known to damage DNA or cells directly. Low- to mid-frequency EMFs include extremely low frequency EMFs (ELF-EMFs) and radiofrequency EMFs. ELF-EMFs have frequencies of up to 300 cycles per second, or hertz (Hz), and radiofrequency EMFs range from 3 kilohertz (3 kHz, or 3,000 Hz) to 300 gigahertz (300 GHz, or 300 billion Hz). Radiofrequency radiation is measured in watts per meter squared (W/m2).
The acronym stands for Electro-Magnetic Fields.
No-radon levels are in constant flux, varying from 2 to ten times. They vary based on a huge number of factors-seasonality, temperature, wind velocity, saturation of groundwater, swings in barometric pressure, and other influences. A typical two-day radon test is just that-a snapshot in time along the continuum of radon levels that the house will experience over the course of the year. The longer the test the more statistically reliable the test results, and tests can be done for anything from 2 days up to a year. The EPA recommendation is for tests to be repeated every 2 years.
Contact your state radon office for information about radon in your local area.
You should test your home afterward to confirm that radon levels have been successfully reduced. This test should be conducted no sooner than 24 hours nor later than 30 days following completion and activation of the mitigation system(s).
Mitigators should not perform this clearance testing on their own systems. Potential conflict of interest can be avoided by using an independent tester.
In addition, it’s a good idea to retest your home sometime in the future to be sure radon levels remain low. Testing should be done at least every two years or as required or recommended by state or local authority. Retesting is also recommended if the building undergoes significant alteration.
Are funds available to reduce high radon levels in rental housing?
There are some federal programs that might be used to help fund radon reduction in homes that are affordable to limited income families. These programs generally give money to local agencies or groups, which then fund the work. Some examples are:
- Community Development Block Grant (CDBG) program—funds rehabilitation and repair of affordable housing. For more information, call the U.S. Department of Housing and Urban Development (HUD) at (202) 708-3587.
- “203k” program—funds rehabilitation and repair of single family homes. For more information, call HUD at (202) 708-2121.
- Environmental Justice Grants—funds community-based organizations and tribal governments addressing environmental concerns of people of color and low income communities. For more information, call the EPA’s Office of Environmental Justice at (800) 962-6215.
Some states have governmental programs that can provide loans for radon reduction work in limited income housing. Some community groups are raising funds from private companies and foundations to pay for radon reduction in limited income homes.
To find out more about federal and state programs, or about how community groups have developed local projects to fix radon problems, owners and residents can contact your state radon office.
The primary benefit is dramatically reducing the risk of developing lung cancer.
Lowering high radon levels requires technical knowledge and special skills.
Many states certify or license radon contractors. Call your state radon office for information about qualified service providers in your state
Both Virginia and Maryland require professional radon mitigators to be listed by one of the same 2 national certification organizations as for testing and to follow specific mitigation protocols.
Here again are the two privately-run national radon programs who are offering proficiency listing/accreditation/certification in radon testing and mitigation.
The National Radon Safety Board (NRSB)
Website: www.nrsb.org
Call: (866) 329-3474
Fax: (914) 345-1169
E-mail: info@nrsb.org
AARST – National Radon Proficiency Program
Website: www.aarst-nrpp.com/wp/
E-Mail: info@nrpp.info or info@aarst.orgFax: (828) 214-6299
Your house type will affect the kind of radon reduction system that will work best. Most are as simple as a tube from beneath the building to above the roof, with a fan installed at some point along its length to suck radon from under the house and vent it above the house. Such systems are called “sub-slab depressurization,” and do not require major changes to your home. These systems remove radon gas from below the concrete floor and the foundation before it can enter the home. Similar systems can also be installed in houses with crawl spaces. These are the most common systems used in our area.
Houses are generally categorized according to their foundation design. For example: basement, slab-on-grade (concrete poured at ground level), or crawlspace (a shallow unfinished space under the first floor). Some houses have more than one foundation design feature. For instance, it is common to have a basement under part of the house and to have a slab-on-grade or crawlspace under the rest of the house. In these situations a combination of radon reduction techniques may be needed to reduce radon levels to below 4 pCi/L.
There are a variety of methods that a contractor can use to lower radon levels in your home.
Sealing cracks and other openings in the floors and walls is a basic part of most approaches to radon reduction but EPA does not recommend the use of sealing alone to reduce radon because, by itself, sealing has not been shown to lower radon levels significantly or consistently.
Your contractor will perform a visual inspection of your house and design a system that is suitable. If this inspection fails to provide enough information, the contractor will need to perform diagnostic tests to help develop the best radon reduction system for your home. Whether diagnostic tests are needed is decided by details specific to your house, such as the foundation design, what kind of material is under your house, and by the contractor’s experience with similar houses and similar radon test results.
Short and long term tests fulfill different needs. The longer the test the more reliable the test results as a representation of average long term exposure, but long term devices are not suitable for tests under time constraints.
Short-term tests are the most widely used and provide information the most quickly . These devices should remain in the building from a minimum of 48 hours up to 90 days, depending on the device.
Long term tests run from 91 days to as much as a year. (Electret devices used by All Pro Services are the only devices suitable for both short and long term tests.)
The EPA recommends that for homes, initial measurements be short-term tests placed in the lowest lived-in level. Short-term testing under closed-building conditions helps to ensure that residents quickly learn if a home contains very high levels of radon. If you are doing a short-term test, close your windows and outside doors and keep them closed as much as possible during the test. If testing for just 2 or 3 days, be sure to close your windows and outside doors at least 12 hours before beginning the test, too. You should not conduct short-term tests lasting just 2 or 3 days during unusually severe storms or periods of unusually high winds.
Radon levels within a building fluctuate constantly. Because radon levels may fluctuate by as much as a factor of two or three, additional testing is sometimes recommended to better assess the average radon level. Though short-term tests are sometimes used, long-term tests are often recommended.
Long-term tests remain in your home for more than 90 days. A long-term test gives a reading that is more likely to reflect the building’s year-round average radon level than a short-term test. Because of season variations in radon levels, the closer the long-term measurement is to 365 days, the more representative it will be of annual average radon levels.
If time permits (more than 90 days), long-term tests can be used to confirm initial short-term results between 4 pCi/L and 10 pCi/L. When long-term test results are 4 pCi/L or higher, the EPA recommends the problem be corrected. Long term results always trump short term results and can be used to resolve conflicting results between multiple short term tests.
Two groups of devices are most commonly used for short-term testing.
Passive devices do not need power to function. All Pro Services uses Electret ion chamber detectors, one of the most popular and accurate types of short-term passive test devices used by professionals, and as a certified laboratory we can perform our own analysis to eliminate delays in shipping and handling.
Active devices require power to function. This group consists of different types of continuous monitors and continuous working level monitors. These tests often cost more than passive testing. Some of the active monitors can provide data on the range of variation within the test period. Some are designed to detect and deter interference. However, they usually require operation by trained testers and there is data indicating that electret ion chambers are marginally more accurate.
All professional services are required to meet a number of steps in a complex Quality Assurance program, including regular calibration of instruments, evaluation of spiked samples of known concentration for comparisons and a number of others. The E-Perm electret ion system used by All Pro Services and the continuous radon monitors consistently test among the most accurate professional tests available.
A radon mitigation system should be installed. A radon mitigation system is any system or steps designed to reduce radon concentrations inside the building.
Costs range from $800 to $2000 in most conventional situations.
Anyone can use a “do-it-yourself” test kit to check their own building. The one-use kits are simple to find and use and are relatively inexpensive.
Obtaining a high-quality independent third-party test is a better option because it produces an impartial result and report. The EPA recommends that you hire a qualified professional to test when you are buying or selling a home for this reason, and both Virginia and Maryland require professional radon measurement testers to be listed by one of the 2 national certification organizations and to follow a specific testing protocol. All Pro Services uses only certified Radon Measurement Specialists for all of our testing and in addition is also certified as a radon laboratory.
Here are the two privately-run national radon programs who are offering proficiency listing/accreditation/certification in radon testing and mitigation.
AARST – National Radon Proficiency Program
Website: www.aarst-nrpp.com/wp/
E-Mail: info@nrpp.info or info@aarst.orgFax: (828) 214-6299
The National Radon Safety Board (NRSB)
Website: www.nrsb.org
Call: (866) 329-3474
Fax: (914) 345-1169
E-mail: info@nrsb.org
Anyone can use a “do-it-yourself” test kit to check their own building. The one-use kits are simple to use, reasonably reliable and are relatively inexpensive. Obtaining a high quality professional third-party test is better because it provides a professional report from certified and disinterested third parties, more likely to be trusted and relied upon.
In Northern Virginia the incidence of radon levels above the federal action level of 4 pCi/L or greater is 28% (nearly 3 in every 10). The only way to know whether or not your home has a radon problem is to test for it. Because the primary determiner of the radon level is the strength of the source under the home, crawlspace and walkout features are no guarantee of a low reading. In fact, testing is recommended for all dwellings including third floor apartments and below!
No. The only way to know the radon level in any home, regardless of its age, foundation type, heating system, air tightness, or building materials, is to conduct a test. Elevated radon has been found in brand new homes and homes over 150 years old.
Absolutely not! Elevated radon levels are incredibly easy and inexpensive to correct. I would never recommend avoiding an otherwise attractive property simply because of a Radon issue. The corrections are too simple and inexpensive to be entitled to that kind of influence.
Most systems are as simple as a tube from beneath the building to above the roof, with a fan installed at some point along its length to suck radon from under the house and vent it above the house. Such systems are called “sub-slab depressurization,” and do not require major changes to your home. These systems remove radon gas from below the concrete floor and the foundation before it can enter the home. Similar systems can also be installed in houses with crawl spaces. These are the most common systems used in our area, are effective against radon levels far in excess of those typical in this area and frequently cost less than $1000.
Absolutely not! It is unlikely that you will find a property significantly lower that does not have a mitigation system in place. If you desire to seek an even lower level, a discretionary mitigation installation may bring the level down to fractions of a picocurie. 4.0 pCi/L is the level at which the government recommends remediation, but there is no prohibition against seeking lower levels.
Absolutely. When one considers the frequency of exposure and the potentially lethal cost of ignorance, all houses should be tested for radon. That’s especially true during the real estate transaction when corrective action is most commonly performed.
No-radon levels are in constant flux, varying from 2 to ten times. They vary based on a huge number of factors-seasonality, temperature, wind velocity, saturation of groundwater, swings in barometric pressure, and other influences. A typical two day radon test is just that-a snapshot in time along the continuum of radon levels that the house will experience over the course of the year. The longer the test the more statistically reliable the test results, and tests can be done for anything from 2 days up to a year. The EPA recommendation is for tests to be repeated every 2 years.
Contact your state radon office for information about radon in your local area.
People often ask if this level is safety based. 4 pCi/L is not a health based level. The EPA states that any radon exposure carries some risk; no level of radon exposure is considered perfectly safe. EPA recommended this mitigation action level in 1986 for several other reasons. First, at lower levels (2 pCi/L, which was the original goal), measurement error increases exponentially. Secondly, elevated levels can be reduced to below 4 pCi/L with cost-effective methods 95% of the time. Finally the law of diminishing returns increases costs dramatically at lower levels. The decision was made not to let the perfect be the enemy of the good. 4.0 is also the level typically used to govern mitigation in real estate transactions, but there is no reason a homeowner cannot install mitigation systems to reduce levels even as low as 2 pCi/L.
There is no demonstrably safe level of radon. After a number of studies of the gas, its frequency and likely impact and the technology available to reduce radon levels, a level of 4.0 pCi/L (which is just a unit of measure like an inch or a pound) was chosen as a sensible compromise between a more desirable level of 2 pCi/L (which is approaching the outdoor atmospheric national average) and a level reliably achievable with current technology.
While radon problems may be more common in some geographic areas than others, any home may have an elevated radon level.
Since the governing characteristic is the strength of the subsurface source, new and old homes, well-sealed and drafty homes, and homes on slabs, crawl spaces and with or without walkout basements can have a problem. Even adjacent town houses can have very different radon levels. Homes below the third floor of a multi-family building are also at risk and so first and second floor apartments should also be tested.
The only way to determine the level is to test. the EPA and the Surgeon General recommend testing all homes below the third floor for radon.
A map of radon zones has been created to help national, state, and local organizations to target their resources and to implement radon-resistant building codes. However, the map is not intended to be used for determining if a home in a given zone should be tested for radon.
Trace amounts of uranium are also sometimes integral to materials used in construction. These include, but are not limited to fieldstone and granite. Though these materials have the potential to produce radon, they are rarely the main cause of an elevated radon level in a building and testing is only recommended if the radon level in the house air is high and does not respond to conventional mitigation.
In 1984, an odd coincidence known as the “Watras Incident” led to the discovery of the highest radon reading ever in Pennsylvania and ultimately urged the EPA to get involved in monitoring radon levels in residential homes.
Stanley J. Watras, a construction engineer at the Limerick nuclear power plant in Pottstown, Pennsylvania, set off the alarm at a radiation monitor installed to ensure that workers were not leaving the building with unsafe levels of radiation on their bodies.
This was quite a surprise, because the plant was still under construction and had not even been filled with nuclear fuel yet — so exposure would have been impossible. Eventually, a team of specialists discovered that Watras was not picking up the radiation at the plant, but from his own home —radiation levels in his home were 700 times higher than the maximum level considered safe.
The specialists discovered that the culprit was radon gas, which had been seeping into his home from underground, according to The Morning Call. Living there was the equivalent of smoking a couple hundred packs of cigarettes a day.
The family moved out immediately, and the home was turned into a scientific laboratory for the long-term measurement of radon and the testing of radon mitigation approaches. After several months, the radon was reduced to an acceptable level, and the family returned. Today, the U.S. Surgeon General and the EPA recommend that all homes be tested for radon.
This raised the question”If it is this high here, how high is it elsewhere?” which led to nationwide random testing and which confirmed the presence of radon almost everywhere. Once this became clear, the next question became “How much of a health threat does radon pose?”
Studies were conducted on miners in Colorado and Wyoming and when the scientists controlled for all other variables, they found that the incidence of lung cancer was much higher for miners in high radon environments. Tumors from radon also manifest differently on the lungs than those from nicotine, tars and other adverse elements.
Radon is a natural, colorless, odorless, tasteless radioactive gas found in many homes, schools and offices. There is no way of telling how much is present without scientific testing.
This is a negligible contributor to radon in air level in most homes. Radon dissolved in water, particularly well water, can be aerosolized during showers and when water is running at various taps. Because these fixtures are only run episodically for limited time, it takes 10,000 pCi /L of water to contribute one picocurie per liter to the air. It is only recommended to test for radon in water if the radon level in the house air is high and does not respond to conventional mitigation.
Most indoor radon comes into the building from the soil or rock beneath it. Radon and other gases rise through the soil and get trapped under the building. The trapped gases build up pressure. Air pressure inside homes is usually lower than the pressure in the soil. Therefore, the higher pressure under the building forces gases though floors and walls and into the building. Most of the gas moves through cracks and other openings. Once inside, the radon becomes trapped and concentrated in the air we breathe.
Openings which commonly allow easy flow of the gases in include the following:
- Cracks in floors and walls
- Gaps in suspended floors
- Openings around sump pumps and drains
- Cavities in walls
- Joints in construction materials
- Gaps around utility penetrations (pipes and wires)
- Crawl spaces that open directly into the building
- Pores in the concrete floor
Nationally one out of every 15 homes has a radon level the EPA considers to be elevated—4 pCi/L or greater. In Northern Virginia the incidence is much higher—28% (nearly 3 in every 10). This is the largely due to the granite formations that form the southern bank of the Potomac River, as well as the two mountain ranges on either side of the Shenandoah Valley. With most people indoors for as much as 90 percent of their day, indoor exposure to radon is a critical concern.
Yes-Radon is a Class A carcinogen and is the leading cause of lung cancer in non-smokers, with anywhere from 15,000 to 25,000 victims a year!
When radon undergoes radioactive decay, at each step it emits radiation in the form of alpha particles and also produces short-lived decay products which are also radioactive. Other than in the scientific world all these products are typically lumped together as ‘radon’, referring to both radon and its radioactive decay products together. Measurement is usually expressed in picocuries per liter of air (pCi/L), which is just a unit of measure (like an inch or a pound). All of these are present in the air and can be breathed, and because they are radio-active they can do cellular damage to your lungs.
Radon is formed by the natural radioactive decay of uranium and radium in rock, soil, and water. It can be found in all 50 states. Once present, radon moves through the ground to the air above. Some remains below the surface and dissolves in water that collects and flows under the ground’s surface.
The same way the ground is made up of potassium and sulfur and other elements, it is also made up of uranium and radium, which occur naturally in the earth. As these deposits decay, they produce a radioactive gas (Radon 222) which rises out of the ground and dissipates into the air. It is perfectly natural stuff-you can find it in the middle of Yellowstone National Park. The problem is that if there is a building in the way, the gas enters the building, gets into the air we breathe and because it is a radioactive gas it does cellular damage to your lungs.
People frequently ask, in the context of home inspections, whether what we’re seeing “meets code”. That’s kind of a loaded question. First of all it’s not a code inspection and we are not code officials. Secondly, the codes are living documents and they vary by jurisdiction and change over time. Property owners are not required to go back and retrofit existing houses. There may be places in the course of the inspection where we’ll say to you “If this were being built today we would be doing it THIS way”, but that’s not to indicate a fault as much as it is to give you the information needed to put in a more modern version or upgrade. There are a few exceptions to this “grandfathering” practice— for example, operable smoke detectors in all currently required areas must be in place anytime the occupant of the house changes. If one engages in remodeling, typically what is being altered must meet current guidelines. In general, a building is only required to meet the standard of the day when it was built. Because these guidelines all have health or safety implications, however, it is always smart to incorporate as much current thinking as you can manage cost effectively.
Even when dealing with new construction, the code is seldom adhered to in absolute terms. It is not a law that is chiseled in stone but rather it is more like a cookbook. A cookbook says that if you cook a chicken in a specific way then you will be pleased with the outcome. It is not saying that this is the only way to cook a chicken–it is simply saying that this specific method works and if you use this recipe then no modifications or study is required.
To that end, codes are prescriptive–they define specific requirements in clear terms. They tell us the specific types and sizes of nails to be used and the specified spacing of support elements or the requirement for smoke detectors in all bedrooms and basements. These are typically not subject to interpretation. Other portions of the codes are performance based, which means that whatever method is used must accomplish certain specified results. An example of this would be the requirement that a deck rail must be able to withstand 200 pounds of pressure applied laterally anywhere along its length, and that a four inch sphere cannot pass through it. Beyond that, any design that accomplishes these goals may be acceptable. So codes not only consist of the language and specifications in the document itself, but also include, by inference, the recommendations and designs of architects, mechanical engineers, structural engineers, and the manufacturers of products who essentially have proven that their method or product will accomplish the same end, merely in a different way.
Inspectors look for methods of work that are typical in our area. If we see something that is atypical, we will draw your attention to it so you can do more research if you so desire.
Indoor Air Quality and Mold
Environmental Protection Agency
Indoor Air Quality (IAQ) Tools for Schools (TfS) Program
IAQ Tools for Schools-Managing Asthma in a School Environment-Additional Resources
Indoor Air Pollution-An Introduction for Health Professionals (online book)
EPA “Mold Remediation in Schools and Commercial Buildings”
University of Minnesota Extension Service and Minnesota Department of Environmental Health and Safety
Mycological Aspects of Indoor Air Quality
School Indoor Air Quality Questions
Questions and Answers on Stachybotrys chartarum and other molds
National Center for Environmental Health
MMWR Weekly publication, March 10, 2000 / 49(09);180-4
Update: Pulmonary Hemorrhage/Hemosiderosis Among Infants—Cleveland, Ohio, 1993-1996
National Center for Infectious Disease, Division of Bacterial and Mycotic Diseases
Index of general information pages
Maryland Department of Health & Mental Hygiene
Questions and Answers About Molds
Maryland Childhood Asthma Program
California Department of Health Services
Environmental Health Investigations Branch, mold publications online (Fungi & Indoor Air Quality)
NC State University, Cooperative Extension
Mold, dust mites, fungi, spores, and pollen Bioaerosols in the human environment
New York City Department of Health, Environmental & Occupational Disease Epidemiology
University of Texas
National Academy of Science, Institute of Medicine
Clearing the Air: Asthma and Indoor Air Exposures (online book)
American Academy of Allergy, Asthma and Immunology
HC Information Resources (AAFA)
Yes. Air duct systems can become contaminated with mold. Duct systems may be constructed of bare sheet metal, sheet metal with fibrous glass insulation on the exterior, or sheet metal with an internal fibrous glass liner, or they may be made entirely of fibrous glass. Bare sheet metal systems and sheet metal with exterior fibrous glass insulation can be cleaned and disinfected. If water damaged, ductwork made of sheet metal with an internal fibrous glass liner or made entirely of fibrous glass will often need to be removed and discarded. Ductwork in difficult-to-reach locations may have to be abandoned. If you have other questions, contact an air duct cleaning professional or licensed contractor.
In general, if you can see the mold or smell the mold there is no need for testing. Reliable air sampling for mold is readily available however if you are in doubt or do not occupy the property. Owners of individual private homes and apartment generally will need to pay a contractor to carry out such sampling, because insurance companies and public health agencies seldom provide this service. Mold inspection and cleanup is usually considered a housekeeping task that is the responsibility of homeowner or landlord, as are roof and plumbing repairs, house cleaning, and yard maintenance.
It must be understood however that there are few available standards for judging what is an acceptable quantity of mold. In all locations, there is some level of airborne mold outdoors. If sampling is carried out in a home, an outdoor air sample also must be collected at the same time as the indoor samples, to provide a baseline measurement. The only real standard of measurement available at the present time is to compare the indoor air samples with the outdoor air sample. If the levels inside are substantially higher than those that are outside then the possibility of a problem is indicated. Because individual susceptibility varies so greatly, sampling is at best a general guide.
The simplest way to deal with a suspicion of mold contamination is: If you can see or smell mold, you likely have a problem and should take steps to remove the mold. Mold growth is likely to recur unless the source of moisture that is allowing mold to grow is removed and the contaminated area is cleaned.
You may suspect that you have mold if you see discolored patches or cottony or speckled growth on walls or furniture or if you smell an earthy or musty odor. You also may suspect mold contamination if mold-allergic individuals experience some of the symptoms listed under symptoms of mold when in the house. Evidence of past or ongoing water damage should also trigger more thorough inspection. You may find mold growth underneath water-damaged surfaces or behind walls, floors or ceilings.
Molds produce health effects through inflammation, allergy, or infection. Allergic reactions (often referred to as hay fever) are most common following mold exposure. Typical symptoms that mold-exposed persons report (alone or in combination) include:
- Respiratory problems, such as wheezing, difficulty breathing, and shortness of breath
- Nasal and sinus congestion
- Eye irritation (burning, watery, or reddened eyes)
- Dry, hacking cough
- Nose or throat irritation
- Skin rashes or irritation
For some people, a relatively small number of mold spores can trigger an asthma attack or lead to other health problems. For other persons, symptoms may occur only when exposure levels are much higher. Nonetheless, indoor mold growth is unsanitary and undesirable. Basically, if you can see or smell mold inside your home, take steps to identify and eliminate the excess moisture and to cleanup and remove the mold.
Yes, if indoor mold contamination is extensive, it can cause very high and persistent airborne spore exposures. Persons exposed to high spore levels can become sensitized and develop allergies to the mold or other health problems. Mold growth can damage your furnishings, such as carpets, sofas and cabinets. Clothes and shoes in damp closets can become soiled. In time, unchecked mold growth can cause serious damage to the structural elements in your home.
Molds will grow and multiply whenever conditions are right—sufficient moisture is available and organic material is present. Be on the lookout in your home for common sources of indoor moisture that may lead to mold problems:
- Flooding
- Leaky roofs
- Sprinkler spray hitting the house
- Plumbing leaks
- Overflow from sinks or sewers
- Damp basement or crawl space
- Steam from shower or cooking
- Humidifiers
- Wet clothes drying indoors or clothes dryers exhausting indoors
Warping floors and discoloration of walls and ceilings can be indications of moisture problems. Condensation on windows or walls is also an important indication, but it can sometimes be caused by an indoor combustion problem! Have fuel-burning appliances routinely inspected by your local utility or a professional heating contractor.
There are substances that are hazardous to everyone and then there are those that only bother an afflicted, usually allergic or immune-suppressed, few.
Radon gas, asbestos and lead based paint have to qualify as the “Big Three” environmental hazards in homes today. Asbestos and lead based paint tend to be confined to homes built before 1980 but radon gas has no respect for age and can affect any home regardless of it’s age or architecture. We also need to examine the need to be concerned about radioactive leakage in the form of radon from stone/granite counter tops as well as from our water.
Every house has mold and allergens and B. There are no pre-defined levels to tell us what is acceptable and what is hazardous. A great deal of individual vulnerability is determined by the strength of your immune system and the other stressors in your life at any given moment. Mold indisputably makes people sick however and so with the assistance of the Center for Basic and Applied Sciences and a degree in Biology from GMU, we have become certified to do mold testing and are happy to do so.
Anyone can use a “do-it-yourself” test kit to check their own building. The one-use kits are simple to use, reasonably reliable and are relatively inexpensive. Obtaining a high quality professional third-party test is better because it provides a professional report from certified and disinterested third parties, more likely to be trusted and relied upon.
No. Feel free to check us out on things like Angie’s List, talk to your friends and neighbors and yes — ask your agent. The truth of the matter is that the agent, first and foremost, needs to protect their reputation which only serves to protect you.
No. The code of ethics of The American Society of Home Inspectors (ASHI) prohibits its members from doing repair work on properties they inspect or from making referrals. This assures that there will never be any conflict of interest by the inspector. Our purpose is to provide an unbiased, objective third party report on the condition of the home. We also refrain from doing any of the abatement or mitigation work as a result of test results from any of our environmental testing.
Our role is to tell you what we see, and what we think the implications are. “Who fixes what” becomes a part of the negotiation process. In most transactions, issues concerning plumbing, electric, heat, air-conditioning, and appliances are governed by provisions in the standard contract for sale as conveying in “normal operating condition”. This means that both buyer and seller have agreed that those components will transfer from the seller in good working order, and typically any repairs to bring the property to that condition are paid for by the seller. Everything else is negotiable. The buyer can ask for everything, the seller can say “No” to everything, and typically there is a “meeting of the minds” somewhere in between. This can include small items and fairly significant items, such as a failed roof, groundwater in the basement, holes in walls, or anything not covered by the five areas listed. After the home inspection, the buyer usually sits down with his or her agent and together they determine what items, if any, they will request that the seller either fix or provide a financial allowance to fix.
Our reports are customized for your property. They typically consist of a cover sheet listing contact information for the purchaser, the agents and All-Pro Services, Inc, followed by a summary that contains a list of items that for reasons of safety, cost, or difficulty are considered to be more significant. The summary is followed by the body of the document which contains, section by section, information on all the issues we discovered and discussed with you about the house. The last section of the document consists of some inspection limitations, and general information comments selected specifically for this property to give you information about how some of the systems work. We include digital photographs AT NO ADDITONAL COST TO YOU to make sure that all parties involved clearly understand our areas of concern.
On the front page you will have a permanent record of the specialist who inspected your house, and our contact numbers. Feel free to call us with any questions that arise after you have had an opportunity to read the document at your leisure. We will happily clarify or expand on an explanation.
Phone consultation is always free!
We have inspected many thousands of houses and still have not found a blemish-less property- there’s just no such thing. Most of the builders whose work we see are reputable professionals building a good serviceable product. Most of the problems we see in new construction occur for a couple of simple reasons.
Through ignorance or disregard, tradesmen will sometimes damage or alter the work of other trades in performing their own work. Wood, that may look insignificant to a plumber as he cuts through it while rushing to finish an installation, may be a mission critical component to the carpenter who put it there!
A tradesman working on a house may be pulled off the job for some reason and the tradesman who replaces him thinks he knows where the first left off… but he’s wrong… the result? We discover that the drain has never been connected to the whirlpool…NOT because of poor craftsmanship, or disregard — a simple error.
A subcontractor who was just not meeting the standards of the site superintendent is pulled off the job… but he already visited your house before they caught it.
It is always easier to get people to repair or replace things on a house – any house – before all the money changes hands. With this in mind we prefer to do our Presettlement Inspections just before the buyer does his final walkthrough with the builder. Our inspection serves a different function than the builder’s walkthrough. We look at the entire dwelling to make sure that it can perform as intended. The builder’s walkthrough is an opportunity for the builder to explain how to operate the stove and the Jacuzzi etc. along with an opportunity for the buyer to use the blue tape to mark areas of cosmetic concern and to ask about functional issues raised by our earlier inspection. Two different sets of concerns are met and two different sets of information are provided to the buyer. We believe the home inspection is just as important in new construction as it is in previously occupied buildings and strongly recommend that all buyers obtain one.
It’s very easy to underestimate the depth of knowledge and the steepness of the learning curve for professional home inspectors. To evaluate a house properly an inspector must know details concerning current construction methods, how and when methods have changed over time, how equipment is meant to age, and how it behaves and looks when it is installed or aging improperly. Unusual and precise details must be mastered, such as the color of a proper gas flame, how far apart outlets are permitted to be, how much distance is needed around a furnace flue, how a deck is properly supported, which concrete foundation cracks are unimportant and which signify potential failure… The list is virtually endless. We also have the advantage of being impartial and objective and can look just at the dwelling—not the yard, distance from work, how many kids live on the street, and other factors that influence the buying decision.
Home inspections focus on function rather than form. This is not a cosmetic review of the property. Dated wallpaper or an avocado sink do not concern us. Our inspections begin with the condition of the exterior focusing primarily on its ability to manage water. We look hard at the roofing and flashing, water management such as gutters and grading, siding detailing and condition. We need to make sure the exterior envelope is able to control water and look to see signs of water damage that may have occured in the past or has started to cause damage in the form of rot or general degradation. Inside, the attic is the place that will frequently yield the most information about the present condition of the roof as well as clues to its past history. We are also looking to see if any trusses or rafters have been cut or damaged and we’re checking for proper insulation and ventilation since they are critical to energy efficiency as well as to the life of the roof.
In the basement we review all of the structure not hidden by drywall or possessions, the central plumbing and electrical systems as well as the heating and air-conditioning systems (temperature permitting – if it’s too cold we can’t check the ac without risking damage to the compressor). We then move on to the living areas where we randomly open and close doors and windows, check available outlets, run all appliances and operate all of the plumbing fixtures. In the process, we will discuss with you any damage or irregularities we see, components that are at the end of their anticipated life, evidence of improper or unskilled workmanship and places where improvements may be prudent or desirable. At the end of the inspection we create the report and a report summary. You will receive a summary of the report on site so that you can make your addendum immediately if needed. You will receive the entire report, with photographs, by midnight that day. Our report summary is not a listing of all the things that we found but rather it is an attempt to prioritize items that are dangerous, difficult, or expensive to correct.
It is also important to note that we are not simply on a fault-finding mission. We have a responsibility to make suggestions for future upgrades that will benefit the property as well as try to educate the purchaser about the location and operation of critical components. We want you-the buyer-to be there!! For most buyers, it’s a valuable learning experience and will help you maximize the benefits of the inspection—particularly from the portions that comprise the orientation and “Home Owner 101”information. By accompanying the inspector you can ask questions while the components involved are right in front of you or are fresh in your mind.
No, you aren’t required to be there for the inspection BUT we highly recommend that you be present. It’s a valuable learning experience for most people and will help you get the most benefit from the inspection. If you are following us you can ask questions directly and we can explain maintenance tips for specific areas. We feel you’ll be able to best understand the finished report and get the most benefit from it by having been there during the inspection.
The time will vary depending on both the size and condition of the home. For most homes, 3 hours is pretty typical. But for larger homes, or homes in poor condition, it may take longer.