Ask The Experts

Environmental & Radon

I have a radon system installed in my house. The radon vent pipe runs from my concrete floor to the outdoors. It has been working fine, but now I’m getting a loud gurgling sound where it comes out of the floor. What can I do to correct this?

The sound that you hear is actually air bubbling up through water underneath your basement floor. To improve the air flow underneath your basement floor the radon system installer removes soil in the vicinity of the pipe that draws the radon out from below the house. In simplified terms, the better the air flow, the more radon is pulled out of the soil. The water table, which is the level below which the ground is saturated with water, can be very close to your basement floor level. (When it exceeds the level of your basement floor, water seeps in.) When the water level is just below your floor it fills the small pit dug out by the radon system installer. The air being drawn up the radon pipe pulls air bubbles through the standing water, causing the sound you hear.

The radon system does not draw the water from elsewhere to below your house. Radon fans are good at drawing air, but are not powerful enough to significantly move water. In fact, over the long term, the system may help to make your basement drier as it exhausts moisture laden air. The water under your floor will not actually be pulled up the pipe, so no damage will happen to your radon system, however, the water may reduce the effectiveness of the system during the period when the water table is high. More importantly, you could end up with water entry into the basement if the water level rises any higher. You should check around the exterior of the house to ensure that excess water is being well directed away from the structure. This would include checking the gutters, downspouts and the slope of the ground. If the high water table and resultant gurgling becomes persistent, it may be advisable to install a sump pump system in the basement. If a sump pump is going to be installed it would be wise to consult with the radon system installer to ensure that the de-watering system doesn’t compromise the effectiveness of the radon system.

I am interested in buying a house that happens to be near a power line. Is there a way to test the house to see if there is harmful electromagnetic radiation coming from the power line?

Using a gaussmeter to test for the presence of the electromagnetic radiation (EMR) produced by power lines is a fairly simple and inexpensive process. This device can also test for the same extremely low frequency radiation from transformers and electrical products found in the home. Some home inspectors provide this service, and the local utility may be willing to take readings. The problem is that, despite at least thirty years of studies, there doesn’t seem to be a definitive answer as to whether the relatively low levels of EMR found in or around homes have any health effects, positive or negative, despite the many negative health effects that have been alleged. The National Academy of Sciences and the National Cancer Institute recently released the results of a major study that failed to find a link between electromagnetic radiation from power lines and cancer, but other health effects may still be proven with further study. Despite the lack of definitive results, it does not seem to us to be a great stretch of the imagination to believe that these manmade energy sources might have an adverse effect on our bodies, and that we should take steps to minimize our exposures until science can be more definitive.

Until health effects, if any, have been quantified, a maximum acceptable exposure level can’t really be set. But to provide some perspective, we have found, from testing we have performed, a typical background level of one milligauss or less in homes as measured by the gaussmeter. And a general consensus has developed over the years that we ought to try to keep exposures in our homes from sources such as power transmission lines below two milligauss. The good news is that extremely low frequency electromagnetic radiation from all sources, including power lines, drops very rapidly with distance. The radiation from power lines is usually reduced to one milligauss or less within a couple of hundred feet or so, depending on the amount of current flowing through the lines. If the power line is closer than this distance from the home, testing may be appropriate. What this rapid decrease over short distances means though is that maybe we all ought to be more concerned about radiation from electrical products that are very close to our bodies; the electric meter just the other side of the wall from our easy chair, the microwave oven just behind our heads when we’re eating breakfast, the TV twelve inches from the kid’s noses, and the electric blanket over our bodies at night. Whether there is a proven negative health effect or not, we could easily adjust our lives to reduce, at least a little, our exposures to this form of radiation.

I recently bought a house with a radon removal system in it. How do I know if it’s working properly?

Most radon enters the home from the soil below the house. A standard radon removal system is designed to remove the radon from the ground below the basement floor before it can rise up into the home. The system usually consists of a plastic pipe installed from the soil below the basement floor to the outdoors with a fan installed in the piping to provide suction on the soil. The suction pulls the radon out of the ground and vents it harmlessly to the atmosphere above the roof line.

A properly installed system will have a device mounted on the piping in a readily accessible area near the suction point to measure vacuum. The most common type is called a U-tube manometer. The clear plastic tubing contains a colored oil. Take a close look at the U-tube on your system. The oil on one side of the tube should be higher than the other. This is the side that is tapped into the radon vent pipe. The vacuum in the pipe created by the fan pulls the oil up on this side. If the oil is even on both sides of the tube, the system is not working. You should also be able to hear the motor, as well as the air moving in the pipe to confirm that the fan is operating. Fans are generally warranted for three years and usually last far longer, but they could fail at any time, so periodically checking on the oil levels in the U-tube should be a part of your normal home maintenance routine. Call the installer, whose name and number should be on the equipment, if you believe the system is not operating.

The only sure way to know if the system is doing its job is to test for the presence of radon. The EPA recommends that homes with radon removal systems be tested every two years to ensure that the system is still working. Most home stores sell relatively inexpensive test kits that will be good enough for your purposes. Generally speaking, though, if the house has not been significantly altered in any way that would affect the barrier separating the house from the soil, and the fan is still working, the radon levels should remain low. Changes to the house that are likely to affect radon entry include additions, sump pump installations, basement bathroom installations, or anything else that would change the foundation or basement floor.

I am going to run some wiring in the attic to a new paddle fan. In your previous article you mentioned asbestos in insulation. Does this include insulation in the attic? If so, how should I deal with it?

It is possible that asbestos fibers may exist in almost any older insulation, however most of the concern regarding asbestos contaminated insulation is centered on vermiculite. Vermiculite is a mineral that expands when heated, rather like popcorn, into a light weight pebble-like material. This crumbly material is usually yellowish or light brown, and was normally poured into place from bags when it was initially installed. The EPA has determined that most vermiculite used as insulation was contaminated with a significant amount of naturally occurring mineral asbestos, and that the asbestos can pose a health risk to occupants under certain conditions. If access to the attic is limited and the material is not likely to be disturbed, causing it to release asbestos fibers, it is not likely to pose a health hazard and it is best that it be left in place. This is the standard recommendation for most asbestos found in the home. However, if asbestos is in a location where disturbance is likely, or if remodeling is going to take place that will disturb the insulation, it should be professionally removed, enclosed, or encapsulated. The good news is that vermiculite used as attic insulation is relatively uncommon. From our experience, only about one in thirty homes has vermiculite in the attic. If by chance you do have vermiculite in your attic, you should, at minimum, take precautions to ensure that the vermiculite does not drop into the room below when you do your work, and you should avoid breathing the asbestos fibers or carrying the fibers into the living space on your clothes. Since vermiculite is a loose flaky mineral, it readily produces dust, and a standard dust mask will not fully prevent inhalation of asbestos fibers. Better masks or respirators are available at stores that sell safety supplies.

You recently wrote that a homeowner can remove asbestos flooring from his home. My contractor says he can’t do my bathroom remodeling project until I have any asbestos removed. How do I know what has asbestos in it?

Your contractor is probably reacting to a recent NYS Labor Law Rule that states that a building permit for remodeling work cannot be issued for any home built before 1974 until an Asbestos Survey is performed by a licensed asbestos inspector. The Survey must indicate that no asbestos containing materials were found in the home that will be disturbed by the remodeling or repair project, or if found, that the asbestos materials have been removed. This has to be completed before the permit is issued and work can begin. The law is intended to protect construction workers from asbestos hazard, but the ruling is likely to be severely disruptive to the remodeling profession, and may put some remodeling projects on hold.

Asbestos was included in numerous building materials throughout the home, including some types of flooring, adhesives, ceiling tiles, plaster, drywall joint compound, wiring, insulation, ductwrap, siding, roofing and more. This means that an Asbestos Survey is likely to require that the inspector take several samples for laboratory testing, resulting in total costs for the Survey that range from $350 on up, depending on the size of the project and the number of various materials that may contain asbestos. This does not include the added cost of asbestos removal by a certified asbestos abatement contractor if asbestos containing materials are found.

If you live in your own home and choose to do the remodeling work yourself, you will not be required to have the Survey or to have any asbestos removed. If you wish to hire a remodeling contractor, and the Survey determines that there are asbestos containing materials that your contractor will disturb in the course of the project, you can personally remove the asbestos and reduce your costs. However, if you choose to do the removal work, do your homework first regarding proper procedures to make sure that your work doesn’t result in greater potential asbestos contamination, and be sure to use proper personal protective gear.

I want to replace my kitchen vinyl flooring, which I am told may be asbestos. Can I do this myself?

Floor coverings and adhesives, as well as many other products, manufactured before 1984 may contain asbestos. Testing would be necessary to know for sure whether the materials you want to remove contain asbestos fibers. For asbestos workers the health risk from asbestos exposure is very high and may include asbestosis or mesothelioma, two potentially deadly diseases. The health risk from the relatively low exposures to asbestos fibers normally found in the home is quite low, especially compared to the risk from exposure to radon or environmental tobacco smoke. At low levels the primary risk from asbestos is lung cancer. While the incidence rate is believed to be very low, it is nonetheless wise to take precautions.

The best approach, if at all possible, is to leave the material alone. In many instances you can install an appropriate underlayment on top of the existing flooring and add your final finished floor on top of the new underlayment. But the added materials can result in trip hazards at doorways or inadequate clearances at appliances such as your dishwasher. If removal is necessary to avoid such problems, hiring a certified asbestos abatement contractor is your best option. However, there is no law or rule that says that you can’t, as a homeowner in your own dwelling, remove the asbestos containing materials. Wear protective clothing, including a proper respirator, wet down surfaces to be removed with amended water (water with a small amount of detergent added), seal off the work area from the rest of the house with plastic sheeting, including any heat registers, and place a small fan in a window to blow air out of the workspace to the exterior. Keep in mind that the less dust produced during removal the better. Avoid any sanding or cutting with a circular saw as you remove the materials. Avoid carting the materials through the house, or seal the materials in poly garbage bags before removal. Most landfills will accept properly transported asbestos waste. Check with your local landfill. Be sure to wipe down all surfaces thoroughly when done.

My house is for sale and was just inspected. The inspector said that my chimney was blocked and the water heater exhaust was coming into the house. I want to know why my carbon monoxide detector didn’t go off.

Assuming that your detector was not defective, the answer of course is that there was not enough carbon monoxide in the air to trigger the detector. This is not surprising for a couple of reasons. First, a clean burning gas appliance actually produces very little carbon monoxide (CO). CO is produced when combustion is poor due to misadjustment of the burner, impingement of the flame against a surface, or insufficient oxygen supply for proper combustion. A poorly adjusted flame, or an appliance in a location with insufficient makeup air can produce significant and potentially deadly amounts of CO. That’s why periodic professional inspection and testing of your gas appliances is so important. The exhaust gases in a clean burning appliance consist primarily of relatively harmless carbon dioxide and water vapor. Getting the exhaust gases out of the house is still important, but the exhaust may not be deadly.

The second reason that the alarm may not have sounded is that standard approved CO detectors aren’t actually very sensitive. They are calibrated to alert you to situations that are deadly, not to simply elevated, and only potentially harmful, levels. In fact, at the relatively low level of 40 parts per million, the standard CO detector will take one to six days to sound the alarm, if at all, but the EPA recommends a maximum exposure to 35 parts per million of only one hour. Some studies have shown health problems from chronic exposures as low as 5 parts per million. You can easily exceed recommended maximum carbon monoxide exposure without being alerted by the average detector.

It is our understanding that the insensitivity of CO detectors was allowed due to the relative inaccuracy of low cost units, and the likelihood of false alarms if they were calibrated for greater sensitivity. If you are interested in purchasing a much more sensitive unit you can learn more at

I am cleaning up my house after it was recently flooded and I am wondering if I should be concerned about lead paint in addition to all the other hazards?

You should definitely be concerned about lead paint issues if you have an older home. Lead paint chips or dust may be ingested or inhaled, leading to elevated blood lead levels. Elevated lead levels can result in significant neurological impairment. Children and pregnant women are at the highest risk. While lead paint was banned from residential use in1978, and its use in homes was waning in the 1950’s, lead could be present in any home from numerous sources, including old furniture, so caution is advisable in any home undergoing major demolition, renovation, or repair.

Three quarters of all homes built before the ban contain lead paint, but that doesn’t mean that all of us living in older homes are suffering from excessive blood lead levels. Intact paint in a well maintained home should not pose a significant risk to the home’s occupants. The real problem arises when peeling paint is ignored, or when repair work disturbs the lead paint, resulting in lead chips or dust. Personal protection should be used when doing demolition work, and work areas should be isolated from the rest of the house if possible. This should include sealing off any ducts and creating negative pressure in the work area by installing fans to the exterior. Sanding of any older painted surfaces should be avoided if at all possible. Cleanup should include the use of a HEPA rated vacuum cleaner, since standard units are likely to blow the fine lead dust around the house. And, most importantly, young children should not be allowed in work areas at any time until thorough cleanup is completed. If you suspect that you or your family may have been exposed, a simple blood test can determine if your blood lead levels are too high.

We are selling our house and the home inspector tested the basement for radon, even though it isn’t finished living space. From what I’ve read he should have tested on the 1st floor. Can I contest the result?

The question of an appropriate testing location for radon has been debated since the EPA established testing protocols in 1993. Radon enters a home from the soil below, so the highest radon levels are likely to be found in the lowest areas of the home. The EPA, in its publication, “Homebuyer’s and Seller’s Guide to Radon,” states that testing should occur in the “lowest level of the home suitable for occupancy….which a buyer could use for living space without renovations.” Suitable for occupancy is in the eye of the beholder. We have seen plenty of completely unfinished basements set up for living, with a carpet on the floor, a couch and a TV, exercise equipment, or a children’s play area. A hobbyist may spend large amounts of time in an unfinished basement, working at his or her projects. In these instances the unfinished basement is being used for living space. Many years ago we asked the EPA for clarification of this issue. Their response was that the appropriate location should be determined by the intended use of the buyer. Therefore, in most instances we defer to the wishes of our client.

On the other hand, a basement with a dirt floor, chronic flooding, inadequate head clearances, primitive exterior access only, or insufficient size to accommodate normal activity, could not constitute living space without renovation no matter what the buyer’s stated intended use. In such an instance you might be successful in contesting the appropriateness of the testing location. Be forewarned though that the radon levels on the 1st floor are typically one half to one third of the levels in the basement. So if the levels in the basement are 10 picoCuries or above, they are likely to exceed an acceptable level below 4 picoCuries on the 1st floor also.

In the future, it might be wise to ask a prospective buyer where he or she intends the radon test to occur if this is a concern for you. The appropriate location could then be negotiated prior to the arrival of the inspector.

My son has a lot of allergies. Can you give us some ideas of what to look for or avoid when we are looking for a house?

There are so many potential allergens in the home, that it would be impossible to avoid them all. It would be wise to consult an allergist to narrow down the potential scope of the problem first. As a general rule however, there are a few main environmental allergens that are responsible for the vast majority of allergic reactions. These are usually mold or pollen related. Dust and dust mites, insect pests, and pet dander, are common vectors for allergens found in homes.

You should be looking for a house that is clean and dry, and easily kept that way. Look for a house without carpeting, heavy drapes, etc., or plan on having these removed, since they will harbor dust and mold. Older homes with dirt floor basements, and damp crawlspaces should be avoided. Mold from these areas is typically drawn into the living space of the house. Definitely look very critically at any older home with living space in the basement. The finishes in these areas usually become moldy. Any house that has had a heavy pet presence should also be avoided. Plan on removing any dense vines, shrubs, or trees around the house that would increase the general dampness.

There is a wide divergence of opinion regarding the best type of heating system for your purposes. It is our opinion that a well designed forced air heating system may be best, since the system affords a built-in means of filtering the air. Top of the line high efficiency replaceable air filters installed at the furnace will help keep the air relatively free of allergens. However, the ducts in any heavily used house should probably be cleaned before occupancy. Also, a forced air system can usually be used to provide the ductwork necessary for a central air conditioning system that will keep the interior air more allergen free in the summer.

Consider a house with a central vacuum system to ensure that dust is exhausted to the exterior when cleaning, and make sure a dehumidifier is installed in the basement to keep humidity levels below 50 percent.