The result of industrialization, commercialization and urban growth has been the increasing amount of traffic in our towns and cities.
This is contributing to traffic related air pollution and it continues to grow despite the growth of cleaner vehicle engines.
As the population grows there are more cars on the road and the problems related to traffic pollution is escalating.
Living in urban areas, surrounded by traffic pollution can’t be good for our health.
Scientists have known that air pollution increases the risk of developing cardiovascular diseases such as atherosclerosis and heart failure, but were uncertain how the two were connected.
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The researchers from the University Of Washington School Of Public Health in Seattle examined the cross-sectional relationship between air pollution and both HDL cholesterol (high-density lipoprotein, commonly known as “good” cholesterol) and HDL particle number in the MESA Air study (Multi-Ethnic Study of Atherosclerosis Air Pollution).
The study participants consisted of 6654 white, black, Hispanic, and Chinese men and women aged 45 to 84 years, who lived in area of high levels of traffic related air pollution.
This study used cohort-focused monitoring campaigns to look at time and place to evaluate air pollution exposure for each study participant.
Exposure periods were averaged to 12 months, 3 months, and 2 weeks before examination and HDL cholesterol and HDL particle number were measured in the year 2000.
The researchers found that a higher exposure to black carbon which is a marker for traffic related air pollution, was significantly associated with lowered good cholesterol levels. This exposure was averaged over a one year period.
A higher particulate matter exposure over three months was associated with lower HDL particle number.
The study found that men and women responded differently to air pollution with lower HDL at higher pollution for both sexes although the magnitude was greater in women.
The scientists noted that lower levels of HDL due to exposure to high levels of air pollution may put these individuals at risk of cardiovascular disease and that changes in HDL levels may appear after brief to medium length exposure to air pollution.
This connection between HDL levels and exposure to air pollution can be explained by a reduction in the number of small, cholesterol-depleted particles or the amount of HDL. This means it cannot deplete bad cholesterol or LDL more effectively and it leaves the average amount of cholesterol in HDL particles higher on a per-particle basis.
As a result, there are large quantities of harmful fat deposits forming in vessels which increase the risk of blood clot and block blood supply to the heart or brain.
Recent evidence has shown that the number and functionality of HDL particles may be a better gauge of HDL’s heart-healthy effects than their actual cholesterol content.
With this study we can slowly understand the biology that works behind the effects that take place on our heart and our health when we are exposed to high traffic pollution, a growing concern in the 21st century.
Source: Arteriosclerosis, Thrombosis, and Vascular Biology
