Traffi Time

A new study by University of Michigan researchers has found that particulate matter in air pollution cause increases in blood pressure levels and damage the functioning of blood vessels within 24 hours. This may be the reason air pollution triggers heart attacks, stroke, and other cardiovascular (CV) events.

Particulate matter (PM) is believed to be the 13th leading cause of death in the world. According to estimates by the World Health Organization, air pollution and particulate matter cause about 800,000 premature deaths a year worldwide.

The research team from the University of Michigan studied adults residing in Ann Arbor, Michigan, and Toronto, Canada.

The team concluded from their findings that particulate matter — not ozone — is the primary cause for rapid rise in diastolic blood pressure, and that this happens only if PM is actually inhaled. The findings also indicate that PM causes impairment of blood vessel functioning even 24 hours after exposure.

A 2007 UCLA study reported a significant link between diesel exhaust and atherosclerosis, or hardening of arteries. With hardened arteries, the risk of heart attacks and stroke are significantly increased. When the diesel particles combine with cholesterol fats, it results in a highly-dangerous synergy whose potential for doing damage is much greater than the individual effects of diesel or cholesterol alone.

Diesel particles carry chemicals loaded with free radicals; the fatty acids contained in “bad” cholesterol (low-density lipoproteins or LDL) produce free radicals during cell metabolism. It appears that the two sources of free radicals work together. Their combination activates genes that cause cellular inflammation — which in turn contributes to cholesterol deposits that clog the arteries.

In 2007, the American Cancer Society said that for every 10 micrograms per cubic meter increase in particulates present in air pollution, there is a 6 percent rise in deaths from heart and lung diseases.

Safety Issues reported last month (“Smog and Premature Death Clearly Linked, April 24) that the National Academy has officially established that short-term exposure to smog is definitely linked to premature deaths. This position ran contrary to the pronouncements of the White House.

The University of Michigan team says that with worsening traffic conditions and heavier air pollution, exposure to particulate matter is endangering the health of millions of vulnerable people.

It should become an urgent public concern of government and legislators to make broad policy changes intended to control air pollution more effectively.

Individuals should also find ways to limit their personal exposure to air pollution.

Safety Tips:

* If you jog, avoid doing so when traffic is heavy. Do not jog behind a bus.
* If you exercise outdoors, do so in the early morning or later in the evening. This way, you avoid the highest levels of air pollution and traffic.