Dirty Air and High Blood Pressure
German Study Shows Link

NEW YORK (Reuters) - People who are trying to lower their blood pressure might want to consider the amount of pollution in the air they breathe in addition to the amount of salt in their food, German researchers report.

In a study of more than 2,600 adults, blood pressure rose in tandem with air pollution levels. Pollution may cause changes in the part of the nervous system that controls blood pressure, which would also mean it could increase the likelihood of heart attacks and other cardiac problems, according to Angela Ibald-Mulli and colleagues from GSF-National Research Center for Environment and Health in Neuherberg, Germany.

The findings are published in the April issue of the American Journal of Public Health, journal of the American Public Health Association (news - web sites).

Investigators measured blood pressure in adults aged 25 to 64 in association with concentrations of air pollutants in southern Germany during two periods: 1984-1985 and 1987-1988. Some samples were taken in January 1985, when air pollution in central Europe was particularly acute and resulted in an increased number of hospitalizations for heart problems.

Concentrations of particulates in the air and to a lesser extent, sulfur dioxide, were associated with an increase in systolic blood pressure of 1.79 mm Hg. Systolic pressure, the upper number in a blood pressure reading, measures pressure when the heart contracts.

Among individuals with other risk factors for heart disease such as increased heart rate, systolic blood pressure rose by 6.93 mm Hg in tandem with air pollutants, the report indicates.

Ibald-Mulli and colleagues explain that air pollution can influence temperature, barometric pressure and humidity levels, which can affect blood pressure.

The new findings support a recent study in 20 of America's largest cities, which linked exposure to common pollutants from cars and factories to an increased risk of death. Another group of researchers estimate that air pollution may be responsible for about 5% of hospital admissions for heart disease.

While it is not clear why pollution is toxic to humans, experts suspect that pollutants inflame the lungs or cause the body to release chemicals that can affect heart function. Exactly how pollution might cause blood pressure to climb remains unclear.

SOURCE: American Journal of Public Health 2001;91:571-577.