|
Delaware has one of the highest cancer rates in the nation.
Approximately 17 deaths a year in Delaware are attributed to asthma complications.
Chemicals in the air, called air toxics, contribute to health problems and risks every day.
State researchers wanted to find out what is in the air and how it affects the health of Delawareans, so they used monitoring technology throughout the state to collect air samples and measure toxins.
“Air pollution is one of the major environmental problems facing our state, not least because it affects respiratory and cardiovascular health,” said Ali Mirzakhalili, Delaware Department of Natural Resources and Environmental Control (DNREC) Air Quality Administrator. “Air pollution affects asthma sufferers, of whom there are more than 70,000 in Delaware alone.”
DNREC recently completed an air toxics assessment study, which included monitoring of five sites throughout the state. The information was released to the public at a forum in Felton on Tuesday, March 28, which allowed residents to learn more about chemicals in the air.
The monitors were set up in Wilmington, Delaware City, Lums Pond near Middletown, Felton and Seaford. Each site used canisters that collected the air every sixth day for 24 hours throughout the entire year in 2003.
Air quality officials also determined health risks associated with air toxics and sources of air toxics during phase one. The next phase will use computer modeling to determine where air toxics pose the largest threat.
“The quality of our air can be a critical factor in determining a quality of life,” said Mirzakhalili. “Effective control of air pollution is a community effort.”
Health risks
Over 100 chemicals were monitored during the study. These chemicals can be grouped into four categories, including volatile organic compounds (VOCs), carbonyls, dioxins and metals. Out of these categories, approximately seven chemicals prove to have the highest health risks. All of these chemicals were found at all of the monitoring sites.
These chemicals are:
• Chromium VI- is a top carcinogen. It has no color or smell and can cause respiratory problems and lung cancer. It exists naturally at small levels, but larger levels in drinking water have caused illness elsewhere in the nation. Sources include chrome plating, leather tanning shops and wood preserving.
• Benzene- is a highly flammable, sweet-smelling liquid found in air, water and soil. Sources include motor vehicles, industrial processes and coal-burning power plants. It is also found in gasoline. Small amounts of benzene are common in food products. Large quantities can cause rapid heart rate, convulsions, coma and death. It can also lower red blood cells and harm bone marrow.
• Sulfur dioxide- is a pungent, poisonous gas that can interfere with breathing even at low levels. It aggravates asthma, emphysema and bronchitis. High levels can cause increased death rates in people with existing heart and lung conditions. It can bind to dust particles in the atmosphere and travel long distances on air currents. It contributes to acid rain and cause harm to aquatic life. Sources of this include coal and oil power plants, refineries. Coal-fired power plants contribute 95 percent of sulfur dioxide emissions. Higher levels are only found in areas near power plants.
• Nitrogen dioxide- is a reddish-brown toxic gas that irritates the lungs and upper respiratory system. It can be fatal in high concentrations. One of the most important features of this toxic is its ability to react to VOCs to form ozone. It contributes excess nutrients in water and can lead to algal blooms in the Inland Bays. Sources of this include high-temperature burning of fuels, motor vehicles and power plants.
• Carbon tetrachloride- is a colorless gas that does not occur naturally. It is also called tetrachloroethane. This is no longer produced, but still lingers in the environment from uses as a refrigeration fluid and in aerosol cans. It is unknown how long it will stay in the air, but it could last up to 100 years. It is banned from use and there are no new sources. High exposure can cause liver, kidney and central nervous system damage.
• Vinyl chloride- is a colorless gas with a mild, sweet odor that is not stable at high temperatures. It is also called chloroethene. It is used to make a variety of plastic products, including PVC piping. Breathing in high levels of this can cause dizziness, sleepiness and even death. It is a known carcinogen. Exposure over a long period of time can cause lung cancer, liver cancer and brain cancer.
• Fine particulate matter- made up of particles smaller than 2.5 microns in diameter. These fine particles penetrate deep into lung tissue and are more likely to cause health problems, including premature death, increased respiratory symptoms and decreased lung function, particularly in children and people with asthma. Sources of this include combustion activities such as fuel burning and motor vehicles.
In 2004 only two pollutants, ozone and fine particulate matter, exceed or meet the national ambient air quality standards (NAAQS). Other pollutants monitored in Delaware are below the thresholds of the standards, which were developed by the Environmental Protection Agency.
“None of the individual chemicals increase cancer risk, but we’re not exposed to just one chemical,” said Cal Baier-Anderson, a health effects educator for DNREC. “We found increased (cancer) risks at all the sites.”
For the Seaford site, Baier-Anderson said the result of air toxic exposure could result in 2.5 additional cancer cases per 100,000 exposed people. This puts the health effect at a level of increased risk according to the scale. The three main chemicals in the air surrounding Seaford are carbon tetrachloride, trichloroethene and chromium.
“There is still work to be done,” said Baier-Anderson. “The take-home message if that we could do better.”
Phase Two
The second phase of the study will create computer models to understand what toxics are in the air throughout the site, based on the data gathered at the five test sites.
Mohammed Majeed, a modeling specialist for DNREC, said the model tells us what monitoring cannot.
“Where there are people and traffic, there are chemicals,” said Majeed. “I take data created by the model and compare it to the monitoring. It’s pretty close.”
DNREC and the EPA joined together to create the Delaware Prototype study, which shows throughout the year where the toxics are and what reactions are caused. This information will then be used by the cancer task force to assess human health risks and by officials to find sources of the toxics.
Majeed said phase two of the study should be completed by the end of the year. Products of DATAS will be helpful in providing air quality information that may assist the process of establishing air quality standards based on risk, establishing control strategies for the purpose of meeting the new standards, assisting the permitting process base in its decisions on cumulative impacts, and improving future emissions inventory work.
Once the models are completed, individual communities will also be able to assess risks and create new regulations accordingly.
Understanding sources
“Sixty-eight percent of air toxics come from mobile vehicles,” said David Fees of DNREC. “These include everything from cars, up to airplanes, chainsaws, lawn mowers, etc. It’s a big category.”
Only 23 percent of air toxics are from factories and power plants. Most of the pollution exists during summer months, with additional traffic on the roads and warm sunlight, which causes chemicals reactions in the atmosphere.
“For every 25 miles driven, a pound of pollution is emitted into the air,” said Fees. “We want all Delawareans to understand the connection between transportation and pollution in the hope they will make a contribution towards solving this environmental problem.”
|
