Ozone Air Pollution Causes Health Problems

Ozone Can Harm the Heart in as Little as Two Hours

A new study shows just how quickly exposure to air pollution can trigger dangerous changes in the heart, even in otherwise healthy young people.

By ALICE PARK | @aliceparkny | June 26, 2012 

Jarek Szymanski / Getty Images

Healthy, young volunteers with no history of heart disease showed unfavorable changes in their heart function after just two hours of exercising while being exposed to ozone, report researchers in the journal Circulation. The changes included surges in markers of inflammation, as well as drops in levels of enzymes that break down clots in the blood vessels — alterations that may explain the link between exposure to air pollution and heart risk.

The study is among the first to document the physiological changes caused by exposure to ozone, a major pollutant formed when volatile organic compounds from industrial waste or car exhaust reacts with sunlight. Previous studies have linked exposure to ozone to heart problems, but had not quantified the precise effect of the pollutant on biological markers of heart and lung function.

(MORE: Mom’s Exposure to Air Pollution Can Increase Kids’ Behavior Problems)

In the study, 23 young participants participated in two hours of intermittent exercise in a lab while being exposed first to “clean” air, and then to air containing 0.3 parts per million of ozone, which is higher than the amount found in average U.S. cities but about the peak level calculated for heavily polluted cities like Beijing, China and Mexico City. (However, the level is equivalent to the amount of ozone someone in an average American city would be exposed to over the course of seven to eight hours.) Scientists then compared readings on various biological markers of heart and lung function between the two sessions, to get a sense of ozone’s impact. Under the ozone conditions, the participants experienced a nearly 99% jump in levels of interleukin-8, an marker for inflammation in the blood vessels. They also showed a 42% drop in plasminogen levels, which lowers the body’s ability to break up blood clots. The study recorded the participants’ readings for only 24 hours after the experiment, and the changes were temporary and reversible: once the volunteers stopped breathing the heavy concentration of ozone, their measurements returned to normal levels. But the results show that ozone can have potentially harmful, and even deadly effects on the heart, say the authors. “This study provides a plausible explanation for the link between acute ozone exposure and death,” Robert Devlin, a senior scientist at the U.S. Environmental Protection Agency’s National Health and Environmental Effects Research Laboratory and the study’s lead author, said in a statement.

(MORE: Traffic Noise Linked to Heart Attack Risk)

“The results complement what are suspicions are, and help us to apply what we know about pollution risk to populations we think are at especially high risk,” says Dr. Tracy Stevens, a cardiologist at St. Luke’s Mid America Heart Institute and a spokesperson with the American Heart Association. The findings highlight the dangers of pollution to people who might already have unstable plaques in their heart vessels, she says, since ozone can trigger a surge in inflammatory markers that drive these plaques to rupture, causing a heart attack. While Stevens says the risks of pollution in aggravating inflammation are known, having data that quantifies the risk as the current study does may help more people to appreciate and address ways to reduce inflammation. The American Heart Association recommends that people with heart disease avoid going out on high-ozone days, and lower their risk of exposure to heavily polluted air, including cigarette smoke.

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Stay Hydrated. You can lose 20 to 48 oz of water per hour during intense exercise.

Running in summer requires extra precautions, hydration

By Grant Gensheimer — Special to the Herald-Leader

Foot-race season is here, and many of us will take to running outside. Whether you are a seasoned runner or planning on running your first 5K this summer, there are some precautions to take to avoid heat exhaustion and heat stroke.

These occur when the body’s own temperature regulatory system becomes inadequate at keeping the body cool.

There are two mechanisms the body uses in the attempt to keep from overheating. The first is one we are all familiar with — sweating. The evaporation of sweat from the surface of the skin helps to cool the body. Only the sweat that actually evaporates from the skin has a cooling effect. All that extra fluid dripping off you during your hot summer run is essentially wasted water.

Sweat can have a hard time evaporating when the humidity level is high, making it all the more important that you take the time to adequately rehydrate.

In addition to sweating, the body will also increase blood flow to the skin in the attempt to lose some of the extra body heat to the cooler environment. While this can help in the cooling process, it has the unfortunate side effect of reducing some of the blood flow to the working muscles. That’s why your two-mile jog that may have been easy in May might become much more difficult in the heat of July or August.

When the temperature outside is higher than that of the body, this method of cooling becomes much less effective. Seek a cooler, shaded area a few times throughout your workout, and try to run in the morning or late afternoon to avoid the hottest part of the day.

When starting a running program, or doing any type of physical activity outside remember these tips in order to stay cool and safe:

■ Give yourself time to get acclimated to the summer heat. Start off running in short, easy bouts and slowly progress. It usually takes around a week of daily exposure for the body to make the necessary adaptations.

■ Stay hydrated. The body can lose anywhere between 20 and 48 ounces of water per hour during intense exercise.

■ Take frequent breaks in a cool, shaded area.

■ For intensive and/or hot training sessions lasting more than an hour consider drinking fluids with electrolytes such as a sports drink.

Increasing levels of nitrates in the water for some areas of California….

Do you have nitrates in your drinking water?

BY WATER QUALITY ASSOCIATION (WQA)
Drinking water contaminated with nitrates made national headlines recently when a University of California-Davis study predicted the presence of nitrates in drinking water will intensify in the years to come across California’s Salinas and Central valleys.

While the Davis’ study hones in on California’s nitrate problem, nitrates impact water quality across the United States.

What are nitrates?
Nitrates form when microorganisms break down fertilizers, decaying vegetation, manures and other organic materials. Principal sources of nitrate contamination include animal waste, fertilizers and septic tanks.

How are nitrates regulated?
Nitrates are regulated in the Safe Drinking Water Act of 1974. The law authorizes the Environmental Protection Agency (EPA) to determine safe levels of potentially harmful chemicals in drinking water. These levels are called Maximum Contaminant Level Goals (MCLG). The EPA sets the MCLG for nitrates at 10 parts per million (ppm).

Where are nitrates a problem?
Nitrate is a tasteless, colorless and odorless compound that homeowners cannot detect unless they have their water chemically analyzed. Municipalities are required to test water sources for nitrates annually and keep nitrates at safe levels. Homeowners with private wells should use a certified laboratory to test their water for nitrates and other contaminants on an annual basis.

Why is it important to regulate nitrate levels? 
Although nitrate is necessary for human and environmental health, high concentrations in drinking water can be harmful. Read more…