Tag Archives: radioactivity

Household Hazardous Waste Disposal

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Previously I wrote, or ranted, about stupid smoke detector design, and at the end of the post I mentioned that smoke detectors have a small amount of radioactive material in them, and thus they should be disposed of properly. I didn’t say specifically how because it really depends on where you live. I live in Virginia, and I have since learned that there is no place in Virginia to dispose of them. My county’s website says they have no way to dispose of them and to try to return them to the manufacturer, but if you can’t find any other way to dispose of them, they can be thrown away in the trash. I contacted Kidde, the manufacturer, and they said they will accept them, you just have to mail the smoke detectors to them. The customer service representative I spoke to said just put “for disposal” on the package, and they will take care of them. I actually had a total of three to return because I had the malfunctioning one plus two ones I had originally bought before I had the hardwired ones installed. So last month, I mailed three smoke detectors back to Kidde. It cost me $6.15, but I now have a clear conscience. This may seem a bit much to some people, but I am an environmental engineer. My career has mostly been dedicated to cleaning up and properly taking care of human and hazardous waste. It has also been about dealing with contamination when waste was not taken care of properly, so there is no way I am going to improperly dispose of waste unless it is completely impossible not to do so.

Here is a fun quirk of United States environmental law, my smoke detectors are non-hazardous because they were used in my house. Those same smoke detectors, if used in a commercial or other non-household setting, are hazardous. Hazardous waste in the US is regulated through the Resource Conservation and Recovery Act (RCRA, pronounced rick-ra). Under 40 CFR §261.4(b)(1), “household waste, including household waste that has been collected, transported, stored, treated, disposed, recovered (e.g., refuse-derived fuel) or reused” is considered to be non-hazardous and exempt from RCRA regulation. There are a bunch of reasons why this exemption is in RCRA, but how you treat your legally-not-hazardous, but technically-hazardous, household waste comes down to a bit of just because you can do something, doesn’t mean you should. However, disposal of household waste is also governed by state and local regulations. Just because federal laws allows you to dispose of household hazardous waste in the trash, does not mean your municipality will because they are the ones who actually have to deal with the waste.

Most people know that fluorescent bulbs contain a small amount of mercury, and thus if you ever break one indoors, you should open the windows and leave the room while the mercury volatilizes. It is because of this mercury that most (or possibly all) municipalities and/or waste disposal companies state that fluorescent bulbs should not be put in the trash. The vast majority of trash in the US is sent to landfills and the rest to incinerators, and mercury does not belong in either of these type of disposal facilities. Also, and just as importantly, the bulbs can easily be broken during transfer from your trash can to the truck, while in the truck (especially if it compacts), at the transfer station, at the disposal site, and all the places in between. If it breaks, the workers can be exposed to the mercury, and thus it is not just about protecting the environment but also the workers.

There is more household waste that is technically hazardous. Aerosol cans can become explosive if punctured. Various cleaning, home maintenance, and vehicle fluids routinely used in household are hazardous to the environment. Conversely, both prescription and over-the-counter (and for that matter illicit) unused drugs should be disposed of in a seal container and put in the trash. Putting unused drugs in the trash is far better for the environment than putting them down the drain where they will eventually get into the waterways. Wastewater plants are not designed to remove chemicals like drugs, but that is a post for another day. [I suppose if someone is trying to dispose of their illicit drugs it is most likely because the police are raiding their house, and they are really not thinking about the environment but about jail, but I still don’t want to drink water with trace amounts of cocaine because some druggie upstream of my water treatment plant was trying to evade arrest.]

The point of all this is, think before you toss something in the trash. Spend a little time on your municipalities website, as most now have them, educating yourself on what can and can’t be thrown in the trash and where things that can’t be thrown in the trash can be disposed. While you are at it, educate yourself on what things can and can’t be recycled in your area. There may be a recycling market in your area for something you didn’t even realize.

Smoke Detector Stupidness

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Last night at 3 a.m. my smoke detectors went off. There really is nothing like being awakened from a dead sleep to that extremely high pitched chirp and a female voice saying “fire, fire.” I, of course, immediately got out of bed and went in search of this supposed fire. There was none to be found. However my smoke detectors assured me there was. I then had to go through the house and pull all five of them from their wiring and in some cases pull out the batteries because pushing the button would not hush them. At 3 a.m., that was so much fun.

When I bought this house it did not have any smoke detectors. It had two wall mounted holders for smoke detectors, one in each the downstairs and upstairs hall. There were none in the bedrooms, and there was no wiring for interconnected ones. I decided early on that as I renovated the house, I would install interconnected wired smoke detectors and bring the house up to current code, even though it was not required. I’m an engineer that way. During Phase 2 of renovations, because the ceiling downstairs had to be opened to install a structural beam, the house lost grandfather status, and interconnected wired smoke detectors now became required by the County. No problem. I was already planning to do it. When it came time to install them, I decided to get combination smoke and carbon monoxide detectors. I had to buy all new ones anyway, so I might as well go for full protection.

This leads me to last night and my need to rant. My detectors are Kiddie brand. I mention the brand because there is an oligopoly of sorts on household fire alert and response equipment. All of them seem to work the same and have the same flaws. Modern houses generally will have interconnected smoke detectors so that if one detects smoke, all the detectors will go into alarm. There should also be one detector in each bedroom and in each hall. Interconnected fire detectors and their location are not universally adopted building code requirements for new construction but are a good idea. If you have a large house, it is possible for one to go in alarm and not awaken a sleeping person in another part of the house. Research has also shown that children do not necessarily wake to a smoke detector at all, in particular the tone. This is partially the reason why voice alarms have been added, but with children, personalized voice alarms with the parent’s voice may be needed to insure children are awakened.

If my detectors detect fire, they set off one set of chirps and say “fire, fire.” If they detect carbon monoxide, they set off another set of chirps and say “carbon monoxide.” If the battery is low, another chirp and “low battery.” Then there is some complicated series of chirp sequences to denote if it was previously in alarm, has malfunctioned, needs replacement, etc. that NO ONE COULD POSSIBLY DISTINGUISH THE MEANING OF AT 3 A.M. Mine were definitely yelling fire last night. As I ran around with a stool trying to figure out what the problem was, the hush button was not working at all. At one point, one of them said carbon monoxide, but I have no idea which one because they are all blaring at me at 3 a.m. The units also have some complicated series of LED blinks to denote in which mode (or possibly mood) it is. This is great, but they are IMPOSSIBLE TO UNDERSTAND AT 3 A.M. Also, as far as I could tell or at least understand, there was no way to figure out which specific detector set off the alarm and thus which one was malfunctioning. Maybe the LED is supposed to tell me this, but I couldn’t figure it out when all I wanted to do is stop the awful noise being blared at me.

Thus if any person who happens to work in smoke detector design happens to read this, these things are too complicated to understand when there is some malfunction or inaccurate alarm. I appreciate the voice that says fire, carbon monoxide, or low battery tells you what the supposed problem is. That makes it much easier to understand than which series of chirps are being blared. However, if you are trying to track down a malfunction, it is impossible. Stopping the blare seems to be impossible short of removing all sources of power. For interconnected detectors, I want and need to known which one started the alarm. I can’t figure out the problem if I don’t know that, ESPECIALLY WHEN IT IS 3 A.M. WHICH IS EVIDENTLY THE ONLY TIME DETECTORS HAVE A FLASE ALARM OR LOW BATTERY.

That ends my rant. While I’m on the subject of fire detectors though, please remember to change the battery every six months. Also, please remember when the detector itself needs to be replaced, never throw it in the trash. Smoke detectors contain a small amount of a radioactive substance. They are perfectly fine to have in your house, but they should not be disposed of in a landfill. Find an appropriate place to dispose of them. [Update: Please see my post Household Hazardous Waste Disposal on how I eventually disposed of my malfunctioning smoke detector.]

Short Term Radon Test Results

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Previously I wrote that I was testing my house for radon. I got the test results back this week, and the test results came back as an average radon level of 2.9 pCi/L. The good news is this is less than the 4 pCi/L action level. The bad news is this is still elevated above average house level of 1.3 pCi/L. This test involved collecting radon over four days. At work, I am currently working on a project that involves looking at the indoor air variability due to radon or volatile organic compounds intrusion from the soil and groundwater. Thus, I know better than most how variable indoor air concentrations can be. They can vary a lot. Therefore, before deciding what to do, I have considered the following items:

  • The test was done in winter under proper closed house conditions. Closed house conditions means keeping the doors and windows closed except for normal entering and exiting the house through the doors. This is not an issue in the winter because it is cold. This is also one of the reasons winter is one of the best time to perform the test, but it also means that the test will lead to higher results than if more open house conditions are maintained. When the weather is nice, I like to open the windows and doors, so that would generally mean at least during those times, the radon concentrations in my house should be much lower.
  • The test was performed over four days. As I stated, indoor air concentrations can vary a lot, and in terms of those fluctuations, four days is relatively short term. Even ignoring the seasonal effect of closed versus open house conditions, the long term average radon conditions could be much higher or lower than 2.9 pCi/L. The reasons are not fully understood, but exterior temperatures and precipitation can affect it. A long term test over several months or even better a year, will give a much better understanding of the average concentration. If the results had been 1.3 pCi/L or less, than given the conditions, I would probably not be at all worried that the long term concentrations would be higher.
  • The EPA recommends that the test be performed in lowest habitable portion of the house. As such, I placed the test in the guest room for that and other reasons stated previously. However, I am almost never in the guest room. I don’t have guests that often, and the door to that room remains shut most of the time. Thus the only air exchange in the room is via the ventilation ducts and a little underneath the door. Furthermore, my bedroom and all the common areas of the house (kitchen, living room, etc.) where I spend most of my time are upstairs and should have lower radon concentrations than the guest room. Therefore, even if the results from the guest room do accurately represent average radon concentrations, they are borderline for taking mitigation action and probably represent the highest levels in the house. While I don’t want to expose my guests to undue risks, especially since my guests are generally people I like or love, do I want to mitigate based on the results from this room?
  • Finally, I’m a scientist, and I believe in validation and replication. This was one test result, and home test kits are generally not considered the gold-standard of any type of test. There is no doubt at least of some amount of inaccuracy with it.

Therefore, I have decided to test the house again, but this time for a longer duration. I have also decided to run two tests simultaneously. I plan to place two testers in the house, one in the guest room again and one upstairs in my master bedroom. I have ordered a long term home test kit that can be used to test between 90 and 365 days. I plan to run the test over an entire year to get a much better indication of what the long term average radon concentrations are in the house. Also, by testing both the guest room and master bedroom, I can better understand what my average exposure is both in terms of the average annual concentration and in the rooms where I spend the vast majority of my time. I will also add that while the guest room is a guest room now, as it is bedroom, legally and real estate-wise speaking, and thus in the future it could be a normal bedroom if my life changes or if I sell the house. Therefore I still consider it important to know what the long term radon concentrations are.

Check back in a year, and I will let you know what happened and how I am proceeding.

Testing My House for Radon

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I’m testing my house for radon, and you should also. Winter is the best time to test your house for radon, which is one of the reasons I am testing it now. What is radon, and why am I testing for it? Keep reading.

What is radon? It is an odorless, tasteless, invisible gas that also happens to be radioactive. It is produced naturally from the decay of uranium, which occurs naturally in soil across the United States, and other countries and continents. The United States Geological Survey (USGS) has this neat map showing uranium soil concentrations across the US. Due to its radioactivity, radon is a carcinogen. In fact, it is the second leading cause of lung cancer after smoking. Radon gas is pretty much everywhere, both outdoors and indoors. Like all carcinogens, there is no safe level of exposure. You can’t completely avoid exposure because it is naturally occurring, but it is best to avoid it if you know it is present.

The US EPA estimates that the average home has an indoor radon concentration of 1.3 pCi/L, this means pico Curies, a unit of radioactivity, per liter of air. If your indoor air is above 4 pCi/L, then they recommend you fix your home. I’ll get to what fixing your home means next. Finally if the indoor air concentration is between 2-4 pCi/L, then they recommend you consider fixing the house. It is in that range that the concentration starts to get high enough above background that you might want to take action.

What happens if the radon concentrations in your house are high? First, don’t panic, your house can be mitigated to reduce the radon concentrations. You can hire a professional to install a mitigation system in your house. A mitigation system can either prevent radon gas from entering the house, or it can remove it from the house once it gets in. For example, one type of system sucks or pulls gas from beneath the house and then pipes it safely above the house where it can disperse into the atmosphere. Mitigation systems can be very effective and will greatly reduce your risk of lung cancer due to radon exposure.

Is your house at risk? As shown in the USGS map, some areas have higher concentrations of uranium in the soil than others. Areas with higher soil uranium concentrations will generally lead to higher radon gas concentrations. Also, houses with a crawl space will generally have less radon infiltrating the house than houses built on a slab or with a basement. The crawl space can allow the radon to dissipate before rising into the house. Houses with cracks in their slab are more susceptible because the cracks serve as a pathway for the radon to rise into the house. Also, pipes and conduits such as for wires from the house to ground can also allow radon to enter if they are not properly sealed.

So how do you find out if elevated levels of radon exist in your house? It’s fairly easy. Many states regulate the testing of radon, so you may try contacting your state radon department if it has one. Most of the time, you can go to your local home improvement store and buy a test kit for about $20. That’s what I did. The test kit I bought included two little containers that detect radon. The test kit had certain specific directions for the test containers such as they needed to be at least three feet off the floor, at least three feet from an exterior wall, etc., and they needed to be open for four days. The test containers were supposed to be placed six inches from each other. I presume you get two that are supposed to be placed in the same location for replicability. So here are the high tech test kits.

Both radon detectors placed for testing

Both radon detectors placed for testing

Yes that is a tape measure in the photo because it said to place them six inches apart, and I’m an engineer. Now be quiet. The detectors should be placed in one of the lowest habitable rooms of the house. My house is built into a hill such that the front door on the first floor is ground level, and the back door of the second floor is also ground level. I chose to place the detectors in the guest room, which is on the first floor and in the back exterior corner of the house. The back wall and 3/4 of the side wall of the guest room are underground exterior walls, and thus this room would be one of the most susceptible to radon infiltration from the ground. The room that serves as my office and workout room is next to the guest in the front exterior corner of the house. Two of its walls are also exterior, but only about 1/3 of its side wall is actually underground. However, there is a crack in the slab about two feet long in the office, so I considered whether the test kits should be placed in this room. [Due to the extensive renovation I’ve been doing on this house, I know where all the cracks and openings are.] That crack could serve as a major route for radon to enter the house. However, I ultimately decided that the guest room would be more susceptible to radon infiltration because of the amount it is underground.

After choosing in which room to place the detectors, I then found a good location that was far enough away from an exterior wall and above the floor. I then proceeded with the testing protocol. I unscrewed the containers and let them sit for four days. Whew, that was exhausting. I deserved a drink after initiating that test. Here is one of the detectors unscrewed. It’s quite simple looking.

Radon detector open to run test

After I let them sit for four days, I screwed the caps back on, filled out the form that came with them, and mailed them into the lab. It cost $30 to have them tested, so with the cost of the kit, the entire thing cost me $50. I consider $50 a small price to pay to make sure I am not unknowingly breathing in a carcinogen everyday. I’m currently waiting for the results from the lab, and I will update my blog when I get the results.

One final note, I said at the beginning of this post that winter is the best time to test for radon. The reason for this is winter tends to be the time that the radon concentrations in a house would be at the highest. When the weather is nice, people tend to open windows  for ventilation instead of using the AC or heater, and people just tend to open doors more often to go outside for whatever reason. Thus in the winter, the house is more closed off, and radon concentrations can build up due to less exchange of the indoor air with the outdoor air. Where I used to live in south-eastern part of US, I probably had windows open more often in winter, as I constantly used the AC in the summer, so this might not hold true. That and the fact that indoor air concentrations can vary day to day, is why experts recommend that if you get high levels detected with a short term test, you consider doing a longer term test such as over several months, to determine what the longer term average is. The test kits do have false positives, especially at lower concentrations, so if you test your house, and it comes back high, once again, don’t panic. Test your house again, this time with a longer term test, and see what the longer term concentration is, and then determine if you need to take action. However, don’t remain ignorant about the risks. Test your house; it’s important and could save your life.

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