A toxin scare gone viral has many unnecessarily fretting over immediately using their car’s air conditioner.
Reducing exposure to environmental toxins is a primary goal for the millions of Americans living with chronic liver disease. Of particular concern to those aiming to minimize their toxin load, heat accelerates the leaching of toxic chemicals out of synthetic materials into air, water and food. Thus, it comes as no surprise that many with liver disease are worried about the heat-induced release of toxins during this country’s recent sweltering summer. An email warning of toxins in hot cars has gone viral and is creating a mass paranoia in those who are concerned about toxic chemical exposure.
Although there are several variations, the email, instant message and Facebook posts involved read something like this:
Car air conditioner (A/C) – a MUST READ!!!
Please do NOT turn on A/C as soon as you enter the car.
Open the windows after you enter your car and turn on the A/C after a couple of minutes.
According to research, the car dashboard, upholstery and air freshener emit benzene, a cancer causing toxin.
In addition to affecting the kidneys and liver, causing miscarriages and cancer, benzene poisons your bones, causes anemia and reduces white blood cells.
Acceptable benzene level indoors is 50 mg per sq. ft.
A car parked indoors with windows closed will contain 400-800 mg of benzene.
If parked outdoors under the sun at a temperature above 60 degrees F, the benzene level goes up to 2000-4000 mg, 40 times the acceptable level.
People who get into the car, keeping windows closed will inevitably inhale, in quick succession excessive amounts of the toxin.
Please open the windows and door of your car – give time for the interior to air out and dispel the deadly stuff – before you enter and turn on the A/C.
Although there is a grain of truth to the hot car propaganda-spreading message, there is a deficiency of solid facts to bolster this warning. Four reasons to dismiss worries generated by this email are:
- No studies could be found supporting the claims described above. A 2007 German study researched the air inside parked cars and did not find a hazard to human health. Their analysis detected some cancer-causing chemicals upon entering a parked car, but these chemicals were present at levels similar to those found in the air of buildings. Some chemicals that are similar to benzene were found, but benzene itself was not reported in the results of this study.
- The dubious email claim described benzene levels in terms of mg per square foot. The standard way to report levels of chemicals in air is mass per volume, such as mg per cubic meter or cubic foot. Thus, this technical flub suggests the initial author(s) had limited knowledge of reports of toxic chemicals in the air.
- The amounts of benzene actually detected by researchers in studies published in reputable journals were much smaller than the amounts stated in the email. A 2006 study summarizing all the data collected to date reported in-vehicle benzene levels from exhaust fumes ranging from .013 mg to .56 mg per cubic meter. This is a dramatically different quantity from the 400 mg to 4,000 mg per square foot reported above (even though mg per square foot is not an accurate measurement of air volume).
- Most of the published studies on benzene levels inside a passenger vehicle were measured under driving conditions – not in parked cars. Several of these studies have found that in-vehicle benzene levels can significantly exceed those outside the vehicle. The higher quantity was mainly attributed to the presence of exhaust fumes – not chemical off-gassing.
Despite these lapses in reason, those with chronic liver disease are right to be alerted to high levels of toxins in their environment. Known to cause a variety of health problems, benzene is a toxic chemical that can contribute to an overload of liver toxicity. Among the 20 most widely used chemicals in the United States, benzene is primarily utilized as a solvent (a substance that can dissolve or extract other substances) and as a starting material in making other chemicals. In the past it was also commonly used as a gasoline additive, but this use has been greatly reduced in recent decades. Benzene is also a natural part of crude oil, gasoline and cigarette smoke.
Especially in cities with known high air pollution levels, some benzene is to be expected in outdoor air due to automobile exhaust and industrial emissions. Thanks to vapors emitted by products such as glues, paints and furniture wax, higher levels of benzene can sometimes be found in indoor air, especially in new buildings. As such, it is logical that the materials inside of a car could release benzene when subjected to heat and enclosure.
Although not nearly as hazardous as the email in circulation makes it out to be, those with chronic liver disease may be concerned about the presence of benzene vapors inside their car. Per the email warning, this could spawn worry that turning on the vehicle’s air conditioner might exacerbate benzene exposure by re-circulating trapped, contaminated air. If that’s the case, there’s no harm done by opening car windows to ventilate before turning on the air conditioning.
For even greater peace of mind regarding minimizing benzene exposure, consider these steps to reduce exposure:
- Avoid cigarette smoke. Since cigarette smoke is a major source of benzene, quit the habit now and avoid secondhand smoke as much as humanly possible.
- Avoid inhaling exhaust fumes. If sitting in traffic on an LA freeway, switch your car’s ventilation to re-circulated air so that you are not breathing in the toxic exhaust fumes from the automobiles surrounding you.
- Limit gasoline fume exposure. Be careful when pumping gas and choose filling stations with vapor recovery systems to capture the fumes (when possible). Additionally, avoid skin contact with gasoline.
- Exert care when in the vicinity of benzene-containing chemicals – like solvents, paints and art supplies. If engaging in a project with one of these substances, make sure it is well-ventilated.
The email warning people to wait before turning on their air conditioner is not completely erroneous, but it is spreading unnecessary paranoia. Those with a compromised liver are advised to minimize their exposure to potentially harmful chemicals. Although ventilation is a generally healthful practice, chemicals inside of a car are much less of a toxic threat than cigarette smoke or exhaust fumes. Nonetheless, if you open your car door on a blazing hot day and detect an off-putting odor inside, by all means, open the windows to get some fresh air before turning on the A/C.
http://urbanlegends.about.com/od/automobiles/a/benzene_in_car.htm, Toxic Benzene in Parked Cars?, David Emery, Retrieved July 7, 2012, about.com, 2012.
http://www.cancer.org/Cancer/CancerCauses/OtherCarcinogens/IntheWorkplace/benzene, Benzene, Retrieved July 8, 2012, American Cancer Society, Inc., 2012.
http://www.cancer.org/Cancer/News/ExpertVoices/post/2011/07/19/Is-your-car-killing-you-with-benzene.aspx, Is Your Car Killing You With Benzene?, Ted Gansler, MD, MBA, Retrieved July 8, 2012, American Cancer Society, Inc., 2012.
http://www.ncbi.nlm.nih.gov/pubmed/11329696, Personal exposure to benzene and the influence of attached and integral garages, Mann HS, et al, Retrieved July 8, 2012, The Journal of the Royal Society for the Promotion of Health, March 2001.
http://www.ncbi.nlm.nih.gov/pubmed/19729200, Investigation of volatile organic compounds and phthalates present in the cabin air of used private cars, Geiss O, et al, Retrieved July 8, 2012, Environment International, November 2009.