ANN ARBOR, Michigan, June 2, 2008 (ENS) – Short-term exposure to low levels of particulate air pollution may increase the risk of stroke or mini-stroke, according to new research conducted in Texas that suggests current exposure standards are not sufficient to protect the public. Stroke is the third leading cause of death in the United States.

The study examined particulate air pollution in the southeast Texas community of Corpus Christi where there is a large petroleum and petrochemical industry presence.

The results showed what the researchers called “borderline significant associations” between same day and previous day exposures to fine particulate matter and risk of ischemic strokes.

Refinery row at Corpus Christi, Texas
(Photo by Maria-Christina)

Ischemic (is-skeem-ic) stroke occurs when an artery to the brain is blocked.

In the study, researchers identified ischemic strokes and also transient ischemic attacks, or TIA, sometimes called mini strokes, that often lead to a stroke later.

Findings suggest that recent exposure to fine particulate matter may increase the risk of these types of stroke events specifically.

Particulate matter is a combination of fine solids such as dirt, soil dust, pollens, molds, ashes, and soot; and aerosols that are formed in the atmosphere from gaseous combustion by-products such as volatile organic compounds, sulfur dioxide and nitrogen oxides.

Particulate pollution comes from such diverse sources as factory and utility smokestacks, vehicle exhaust, wood burning, mining, construction activity, and agriculture.

“The vast majority of the public is exposed to ambient air pollution at the levels observed in this community or greater every day, suggesting a potentially large public health impact,” said Lynda Lisabeth, lead author and assistant professor in the University of Michigan School of Public Health, where the research is based.

Despite the fossil fuel industry in the area, fine particulate matter exposures were low relative to other regions of the country, the researchers said probably because of the proximity to the coast and prevailing wind patterns.

Lisabeth stressed that the association requires further study in other areas with varying climates and alternative study designs.

Ischemic stroke is by far the most common kind of stroke, accounting for about 88 percent of all strokes. Stroke can affect people of all ages, including children.

Many people with ischemic strokes are 60 or older, and the risk of stroke increases as people age. At each age, stroke is more common in men than women, and it is more common among African-Americans than white Americans.

For this study, researchers looked at data from the Brain Attack Surveillance in Corpus Christi Project, a population-based stroke surveillance project designed to capture all strokes in Nueces County, Texas.

Ischemic stroke and TIA cases between 2001 and 2005 were identified using trained staff and later verified by neurologists.

Daily historical air pollutant and meteorological data were obtained for the same time period from the Texas Commission on Environmental Quality’s Monitoring Operations database.

Data on fine particulate matter and ozone from a centrally located monitor in Corpus Christi located upwind of the local industrial facilities was used in the study.

The majority of stroke and TIA cases were found to be located upwind of local chemical plants and refineries.

Some research has shown that particulate air pollution is associated with acute artery vasoconstriction and with increased thickening of the blood, which may enhance the potential for blood clots.

Similar associations were also seen with ozone, another type of air pollution.

This study confirms earlier research showing that exposure to fine particle matter air pollution increases a person’s risk for hospital admission for cardiovascular and respiratory diseases.

The study, “Ambient Air Pollution and Risk of Ischemic Stroke and TIA,” will be published in the July 2008 issue of Annals of Neurology www.interscience.wiley.com, the official journal of the American Neurological Association.

View This Story On Eco–mmunity Map.

Recently, there have been many murmurs questioning the carbon reducing ability of the biofuel industry. One scientist in particular, Mr. Joe Fargione of The Nature Conservancy, says that statistical research has shown that biofuel production, as it currently exists, produces more carbon pollution than traditional fossil fuels. Keep in mind that this article is in no way an endorsement of the fossil fuel industry. At the end of the article there are some suggestions as to how the biofuel industry can modified to make less impact on the climate.

The two main reasons that biofuels are currently disastrous for the environment have to do with the way in which the alternative fuel source is manufactured.

1. Crops are not being rotated in biofuel farms. Previously, corn farmers would rotate soy bean crops in between harvests of corn. This has been a farming practice since the Renaissance, and helps to insure soil quality improves gradually and requires less fertilization. Previously these corn farms were creating a food stock, and therefore the regulations for food production were in effect; most regulations attempt to insure an edible product as well as mitigate damage to the environment. Producing corn for biofuel is different in that nobody will consume this corn. Since the corn is no longer regulated as a food product, why would you waste money growing a crop of soybeans in between your next harvest of biofuel-bound corn? Instead, it is more financially rewarding to harvest another crop of biofuel and use cheap and semi-toxic fertilizers to insure a large crop of corn. The runoff of toxic, petro-chemically produced fertilizers helps to weaken ecosystems that would otherwise trap carbon in soil, organisms and plants.

2. Converting wild land into a farm with one massive crop of corn releases a huge amount of carbon trapped in soil and wild plants. Joe Fargione says “Let’s say you drain and clear an Indonesian peat bog and replant it with palm oil for biofuel. Over 50 years, the carbon released by the decomposing peat would end up being 420 times greater than the carbon saved by using one year of palm biodiesel. This means that it would take 420 years of using that biofuel to “pay off the debt” of carbon that is released by draining and clearing peatland.” In addition to this, opening up new tracks of agricultural land for nonfood production creates an unsustainable demand on the ecosystem that will accelerate global warming and species extinction.

3. The next problem with biofuel stems from economic supply and demand reasons. Since the aforementioned American farmers are no longer growing soybeans, someone has to step in and grow the product and meet demand. South American farmers have gleefully stepped into this role and are now converting huge tracts of previously wild amazon into soybean farms, hastening the breakdown of these vital ecosystems.

4. Biofuels hold less energy per gallon of fuel, thereby creating more carbon emissions through the transport of the liquid fuel.

Before you black out from the depressing list of problems, remember there is always a new way to look at an old industry. If biofuels were created from cast-off agricultural products and byproducts, then the fuel source would be lowering carbon emissions and bolstering the economy through domestic production of a product. This would limit the amount of production possible at each biofuel distillery, but in the long run would improve the profits of the particular agricultural company because they would lower fuel costs and/or be able to sell excess fuel locally. Intrinsically, there is great value in the production of biofuels, it is just a matter of perfecting the manufacturing process and specifically in harnessing the supplementary energy prospects of intelligent waste management protocols.

Want to read the article this story is based on? Check out the article here [www.nature.org].

Majora Carter and Simran Sethi care about the environment. They have many areas of knowledge on various environmental subjects. The two hosts made a few green editorial videos that played during the first screening of THE GREEN programming block. These videos deliver bite-sized bits of information that make it easier to present simplified versions of very confusing issues.

These green editorials also refer to some of the documentaries that play on Sundance Channel. Make sure to keep a note of the documentaries that interest you and tune-in to Sundance Channel the next time that documentary airs.

Green Editorial #1: Introducing the Hosts and Fuel Issues

This piece engages the fossil fuel industry and connects the dots between the oil well, your gas station and your tank of energy. This brings up the documentary CRUDE AWAKENING.

Green Editorial #2: Majora Carter and the Sustainable South Bronx project

This video with Majora Carter focuses on some important issues of pollution and poverty and how the two are often found in the same places.

Green Editorial #3: Simran Sethi and Vegetable Gardens

Simran Sethi shares her knowledge about the lawns in America and whether laboring that hard on grass is really worth it.

We trust you enjoyed these video pieces, and we’ll keep these coming in the near future.