In Thailand, particularly in Bangkok and metropolitan region, a massive cloud of ultra-fine dust particles known as PM2.5 has recently returned. According to the World Health Organization (WHO), the concentration of PM2.5 pollutants should not exceed the safe threshold of 10-25 µg/m³. If the number is greater than this threshold level, these fine particulate matters can substantially cause a wide range of health problems including respiratory disease and heart disease e.g. heart failure and heart attack. Avoidance of pollution exposure greatly helps to prevent health related conditions caused by PM2.5.
Fine particulate matter (PM2.5) and heart disease
Ambient particulate matter (PM) is defined as the material suspended in the air in the form of solid particles or liquid droplets. These fine particulate matters are mainly derived from both human activities and natural sources. It is a mixture with varying size and chemical compositions. In terms of their potential influence on human’s health, according to their diameter, they are classified into PM10, PM2.5 and ultrafine particles (UFPs). Air pollution is a modifiable risk factor for cardiovascular disease. A number of clinical researches firmly indicates that long-term exposure to fine particulate air pollution is associated with increased risks of cardiovascular disease. Statistical data reviewed by World Health Organization (WHO) has suggested that approximately 20% of cardiovascular deaths are caused by excessive exposure to air pollution including PM2.5 and more than 3 million people die from this cardiovascular cause every year.
According to the recommendation made by WHO, long-term exposure to excessive amount of PM2.5, over 10-25 µg/m³ can potentially cause inflammation, impaired coagulation process and damages to blood vessels. These eventually cause cardiovascular and respiratory diseases as well as cancers. Several pathways have recognized to explain the strong linkage between PM2.5 and cardiovascular diseases. Causing acute effects, PM2.5 can directly translocate into the blood stream, causing weakened vessels and increased risks of vessel ruptures. In patients diagnosed with cardiac diseases, sudden impacts of PM2.5 can also cause the exacerbation of heart disease. For long-term consequences, PM2.5 can alter biological changes in the cells, causing inflammatory response all over the body and thickening blood vessels as well as inducing pulmonary oxidative stress. Interestingly, these effects are equivalent to those found in tobacco. In the near future, exposure to PM2.5 will be considered one of major risk factors contributing to cardiovascular disease.
Effects of air pollution on heart health
Statistic data obtained from European Society of Cardiology (ESC) suggests that the number of deaths from cardiovascular disease can be attributed to air pollution is much higher than expected. In Europe alone, the excess number of deaths is nearly 800,000 a year and each of these deaths represents an average reduction in life expectancy of more than two years.
Information derived from ESC says “by using a new method of modeling the effects of various sources of outdoor air pollution on death rates, the researchers found that between 40-80% of these deaths were due to cardiovascular diseases such as heart attacks and stroke. Air pollution caused twice as many deaths from cardiovascular diseases as from respiratory diseases. In addition, researches have pointed out that air pollution causes 8.8 million extra early deaths a year worldwide, instead of 4.5 million as previously estimated. This figure draws a conclusion that exposure to air pollution might be the most common contributing factor to cardiovascular deaths. To lower the risks, smoking cessation might be considered while air pollution cannot be completely avoided.
Not only cardiovascular disease, but exposure to air pollution also strongly associates with respiratory diseases. Health-related problems include hypertension, diabetes, heart failure and heart attack with increased mortality rates.
Tips for coping with PM2.5
Dr. Chattanong Yodwut, cardiologist and the director of preventive heart center, Bangkok Heart Hospital points out the serious impacts of PM2.5 on heart health. Excessive exposure to PM2.5 can directly translocate into the blood stream, causing damages to the vessels. Furthermore, PM2.5 can alter coagulation pathway and biological changes in the cells, causing inflammatory response and increasing risks of heart failure and heart attacks. Apart from smoke cessation, avoidance of pollution exposure greatly helps to prevent health related conditions caused by PM2.5. If any symptom arises, immediate medical attention is required.
By Dr. Chattanong Yodwut
Cardiologist and the director of preventive heart center,
Bangkok Heart Hospital.