Air Quality in Minnesota
No city in Minnesota can compete with Los Angeles or Houston on air pollution levels. Minnesotans are unfamiliar with “ozone alerts.” An ozone alert is declared by the government when pollution (ozone) in the air reaches a level that poses health risks to sensitive populations (elderly, children or anyone with compromised health). Typically, sensitive individuals are advised to stay in air-conditioned spaces.
Although the situation in Minnesota is not yet that severe, air quality problems do exist. If you look closely, you can see a brown layer of crud on the horizon around the Twin Cities. Some air pollutants are causing negative health impacts in our citizens. Others are falling out of the air and creating other concerns in our lakes and streams. This article will briefly outline some of the major air pollutants in Minnesota, including smog, fine particles, air toxics, greenhouse gases and mercury, and why we should be concerned.
Smog (also called “ground-level ozone”) is created when the sun “cooks” pollution from cars, trucks and power plants in the air. The levels of smog in the Twin Cities are currently within the range allowed by law, but they’re close to the limit. Even at legal levels, smog may impact human health and the environment. Ground-level ozone is linked with respiratory problems, including exacerbated asthma, and adversely affects the growth of plants.
Little bits of soot and pollution, usually referred to as “fine particles,” are also a human health threat. Again, levels of fine particles do not exceed legal limits in Minnesota, but strong scientific evidence links the presence of these chemicals, even at low levels, to heart and lung disease, cancer, asthma attacks, and death. Particles are released directly into the air by coal-fired power plants, cars, and wood burning. They are also formed by chemical reactions of other pollutants in the air.
“Air toxics” refers to a broad group of chemicals released into the environment that may cause health problems for people. The sources and effects of these chemicals vary widely, although the largest source of many of these chemicals is motor vehicles. Most people are exposed to a wide variety of these pollutants every day. The levels of these pollutants are mainly below health-based guidelines, but the cumulative impacts of many chemicals on the body are not well understood by scientists. In addition, the health effects of mixtures are unclear.
Greenhouse gases, pollution that contributes to global warming by trapping heat in the Earth’s atmosphere, are mainly released into the air by the burning of fossil fuels. Fossil fuels are natural gas, oil and coal. The main culprits are coal combustion for electricity and gasoline burning for transportation. Carbon dioxide, the main greenhouse gas, is not toxic to people (we exhale it when we breathe), but global warming does pose several possible threats to Minnesotans. A warmer climate would change the character of our forests and wildlife, possibly reducing the populations of walleye and other cold-water fish. Tropical diseases also will begin to move north, such as the West Nile virus that recently appeared in the Northeast. It is important to note that the science showing that human activity is influencing the global climate is strong. Due to atmospheric complexities, predicting the exact effects of global warming on specific regions is difficult, but we do know that we are making an impact.
The imposingly titled “persistent, bioaccumulative toxics” are perhaps the scariest of the air pollutants. The term “persistent” means these pollutants are not naturally destroyed in the environment. “Bioaccumulative” means that the chemical “builds up” in the food chain. For example, a small microorganism may eat one of these chemicals. Then a fish eats many microorganisms, exposing itself to more of the chemicals. Then a person (or an eagle, otter, etc.) eats several fish and the pollutants build up in the person. Many of these chemicals fall out of the air and land in water or soil. Mercury, dioxin and many pesticides are examples of this class of pollutants. Health impacts include cancer, neurological and reproductive effects and developmental problems. These chemicals are especially problematic because the health effect may occur to the offspring of those people exposed, making it difficult to determine the cause. Sources of these chemicals include pesticides, waste incineration and coal burning.
What is the link between the different pollutants? Many are created and released during energy production or, more specifically, fossil fuel combustion. The cars we drive and the coal we burn for electricity create many of these problems. Other pollutants are fossil fuel-derived, including pesticides and materials used to make plastics. We can all reduce the emissions of these chemicals (and our own exposure) by reducing the amount of fuel we burn.
Overall, Minnesota’s air quality is similar to most other places in the United States. We enjoy lower levels of smog and some air toxics, but similar levels of many other pollutants. Greenhouse gases, fine particles and persistent chemicals are not Minnesota-specific problems. Air pollution should be a concern, however, and Minnesotans should do what they can to reduce their contribution and exposure when possible.
|Sidebar: Dioxin and Other Chemicals in Alaska Found to Come From MinnesotaWinona LaDuke, The Circle News, August 2001|
Emissions from U.S. incinerators find their way directly to the Arctic. A study says toxin from the Xcel-owned incinerator in Red Wing, MN, has been found in breast milk in Alaskan women in Port Graham. With the help of new sophisticated tracking mechanisms, it is found that the residue of our own garbage is what is in their milk.
Researchers from the NACEC studied some 44,000 sources of dioxin in North America. They tracked them into the pristine ecosystem of Nunavat. Nunavut, an almost entirely Inuit region of Canada, is considered an ideal test ground since there are no significant sources of dioxin in the territory, nor within 300 miles of its boundaries.
In the top ten sources of dioxin found in the Arctic, two identified sources were the Xcel-owned incinerator in Red Wing, MN, and the incinerator at French Island in LaCrosse, WI. Overall, U.S.facilities, primarily medical waste and garbage incinerators, were found in the NACEC study to contribute 70 to 82 percent of all dioxin deposited at the eight test locations in Nunavut. Canadian facilities, by comparison, contributed 11 to 25 percent, and Mexican sources contributed between 5 and 11 percent.
The pulp and paper industry ranks as the leading source of dioxin exposure to the public, a direct consequence of the use of chlorine bleaching in their processes. Second after that is waste incineration, and Minnesota burns three million tons a year, more than any state except New York. Those waste incinerators are spewing out dioxin that ends up in pastures and on food crops, and eventually in our bellies. Considering that we produce a lot of our dairy, cheese, and other foods in the St. Croix River Valley, we might want to take an interest in the contamination in our own backyard.
Fortunately, there are initiatives underway to reduce toxic emissions in both Canada and the U.S., including new EPA regulations which should reduce dioxin emissions by 90 percent from municipal waste incinerators and 95 percent from medical incinerators. Although, it is important to note that incinerators do not make waste “disappear,” they simply reduce it to ash and atmospheric emissions, both of which are still incredibly dangerous. In fact, up to 40 percent of the waste is still around.
There are more immediate solutions, such as recycling, re-using, and eliminating many of the things we send to the dump and incinerator. There is work underway to negotiate the Treaty on Persistent Organic Pollutants. Here at home, our own incinerators need a cleanup. That would be our work.
|What You Can Do* Drive the most fuel-efficient vehicle that meets your needs.|
* Decrease home electricity use. Buy efficient light bulbs, ceiling fans (over air conditioning) and low flow shower heads (if electric water heater); line-dry clothes; and install efficient A/C unit and refrigerator.
* Decrease energy use for heating. Install better insulation and turn down thermostat in winter when house is empty.
* Avoid pesticide use and exposure.
* Do not buy an SUV. The Union of Concerned Scientists says that, for most Americans, transportation choices create the biggest impact on the environment.