Benzyne And Acrolein

History of Air Pollution

Top Sources By Percentage

• Humans first felt health effects from air pollution when they built fires in poorly ventilated caves. • Throughout most of history, air pollution problems have been local and minor because of the earth’s ability to absorb and purify pollutants • Since the mid-1700’s the industrial revolution, cars, and a huge boom in the population have caused a more widespread pollution problem • One of the worst cases of air pollution occurred in London in 1953 when smog rolled over the city and killed 8,000 people over a six month period. • Today, it is believed that burning fossil fuels cause the greatest health risks. • Sources of air pollution can be divided into two categories: anthropogenic sources (human activity) and natural sources. •The EPA monitors 177 different pollutants. Two • The most prevalent anthropogenic sources of major pollutants are benzene and acrolein. air pollution are smoke stacks of power plants •“From a national perspective, benzene is the and factories, motor vehicles, and aerosol most significant air toxic for which cancer risk sprays. could be estimated.” • The most egregious natural sources of •“Of the 40 air toxics showing the potential for pollution include naturally produced dust, respiratory effects, acrolein is the most methane emitted by animals, smoke and CO significant, contributing 91 percent of the from forest fires, and sulfur, chlorine, and ash nationwide average noncancer hazard identified produced by volcanic activity in this assessment.” Symptoms caused by Benzene: •drowsiness, dizziness, headaches, and unconsciousness •vomiting, convulsions (ingestion) •skin, eyes, respiratory tract irritation •blood disorders (bone marrow) •Possible infertility in women •increased incidence of leukemia (benzene is a recognized carcinogen) Symptoms caused by Acrolein: •High concentration = death •Respiratory congestion •Eye, nose, throat irritation •Skin burns

Major Sources

Benzene and Acrolein

Benzene Mobile Onroad

49%

Mobile Nonroad

19%

Open Burning

14%

Acrolein Open Burning

61%

Mobile Onroad

14%

Mobile Nonroad

11%

What is being done? What more can be done?

Clean Air Act- originally implemented in 1970-revised in 1990 by (EPA) Environmental Protection Agency - goals: •reducing outdoor, or ambient, concentrations of air pollutants that cause smog, haze, acid rain, etc. •reducing emissions of toxic air pollutants that are known to cause cancer or other serious health effects (such as Acrolein); and •phasing out production and use of harmful chemicals •Alternative Motor Vehicle Credit applies to hybrid vehicles purchased after January 1, 2006. The credit is worth up to $3,000 for the most efficient models. This credit should significantly reduce Benzene production. •The Occupational Safety and Health Administration has a long-term exposure (8-hour shift) limit of 1 part per million (ppm) and a short-term (15 minutes) exposure limit of 5 ppm for Benzene. •As for Acrolein, the administration has limits of 0.1ppm over a 10 hour work shift and 0.3ppm over any 15 minute period