Cerebrovascular problems linked to air pollution: study

Air pollution may contribute to cerebrovascular problems such as strokes, according to a recent published study.

The study, published in the European Heart Journal, suggested that as the concentration of specific pollutants increases in the air, the risk of people suffering from pathological changes in cerebral vessels also rises.

Those who are at higher risk of strokes are therefore advised to avoid areas with heavy air pollution or ideally move to areas where the air quality is better.

As the concentration of ozone and carbon monoxide grows, daily emergency admissions of patients with cerebrovascular problems to hospitals increase, said the study, which was undertaken by the Institute of Occupational Medicine and National Taiwan University's Institute of Public Health.

The finding was based on a cross-analysis of Taipei's air quality and the number of daily emergency admissions to the National Taiwan University Hospital through 1997 to 2002.

Chan Chang-chuan（詹長權), a professor at the institute, estimated that once ozone levels become poor, the number of patients with cerebrovascular ailments who are hospitalized tends to grow by 10 percent.

Chan said increasing evidence showed that air pollution not only causes allergy, asthma, deterioration of pulmonary function and cancer, it may also lead to cardiovascular and cerebrovascular diseases.

No one is immune, he added.

Air pollutants may cause inflammations all over the body and pathological changes in blood vessels once they are inhaled, he said.

Air pollutants also contribute to disorientation of the autonomic nervous system, which results in cardiovascular illness such as high blood pressure, Chan explained.

Additionally, there seems to be a regional difference in the relation between air pollution and cerebrovascular diseases.

According to research conducted at Kaohsiung Medical University, as the amount of suspended substances and the concentration of nitrogen dioxide in the air increase and so does the rate of strokes on days when the temperature exceeds 20?C.

However, the risk only applies to Taipei City when it is cold.

Chan suggested people who have a higher risk of suffering from cardiovascular illness should stay away from air pollutants such as the exhaust fumes of cars and scooters.

Chan also mentioned that the air quality in suburban areas may not necessarily be better than that in urban ones because of geographical, climate and industrial differences.