A recent study in America found evidence for increased levels of IL-1 beta, a marker associated with inflammation in the blood of people who lived near the highways and had high exposures to vehicular exhausts.
As our consumption and usage of vehicles increases, our roads constantly brew more particulate matter, black carbon, nitrogen dioxide, sulphur-di-oxide and carbon monoxide, all emitted from automobile exhausts. The danger about these emissions is that they don’t just stay there, but drift. Our busy highway and motorways, which have high traffic volume, are the worst offenders. Studies indicate that people living/working in such areas and spending significant time within approximately 200m of highways are exposed heavily to these pollutants compared to people who are based further away. Unsurprisingly, the exposures at highways are higher when compared to people living on busy urban streets.
A plethora of studies have linked vehicular emission
exposure to heart disease. We had highlighted a couple of them in this blog. The
closer people live or work near highways/motorways, the greater is their exposure to the harmful effluents. However, many of the studies in this field of research are epidemiological in nature which are population based and subject to the criticism that the observed
correlation in the studies might not really signify causality. A recent study
by researchers from Tufts School of Medicine, Boston, attempts to close the gulf and provides a molecular basis of the effects of vehicular
emission exposure on human health and offers an explanation on how automobile exhausts could cause heart diseases.
The study was conducted in the Somerville area of Massachusetts, USA. The scientists compared blood samples from 20 people who lived less than 100m from the Interstate-93( a highway that connects Massachusetts to Vermont) and those residing a km away from the highway in urban backgrounds. To ensure that the two groups were as similar as possible, the subjects in both groups were matched to age, gender and education. Though there were no significant differences between two groups in terms of body measurements (height, weight) and education, the group who lived in urban backgrounds were more likely to earn less, had higher exposure to vehicle exhausts that was occupationally related and high
levels of bad cholesterols (LDL). The researchers
factored the job related vehicle emission exposure in their calculations and
found that the levels of IL-1 beta was increased significantly in those people who lived near
the highway.
Inflammation plays a crucial role in the development and progression of a variety of heart diseases importantly atherosclerosis and congestive heart failure. Inflammatory molecules linked to these processes includes interleukin-1 (IL-1), but this American study is the first of its kind where such a link has been shown to occur in humans with proximity to heavy traffic. The results are notable as it also recapitulates the trend shown by particulate matter in increasing the levels of IL -1 family in animal models and cells in culture. In their paper, the researchers also point out that IL-1 beta itself could have application as a biological marker of air pollution exposure. However, one thing to note is that IL-1 family is also influenced by diet and this is a factor that has to be controlled for in further experiments. Cumulatively, the study by Professor Brugge and his colleagues is a very interesting preliminary work which warrants larger carefully controlled follow up studies.
Inflammation plays a crucial role in the development and progression of a variety of heart diseases importantly atherosclerosis and congestive heart failure. Inflammatory molecules linked to these processes includes interleukin-1 (IL-1), but this American study is the first of its kind where such a link has been shown to occur in humans with proximity to heavy traffic. The results are notable as it also recapitulates the trend shown by particulate matter in increasing the levels of IL -1 family in animal models and cells in culture. In their paper, the researchers also point out that IL-1 beta itself could have application as a biological marker of air pollution exposure. However, one thing to note is that IL-1 family is also influenced by diet and this is a factor that has to be controlled for in further experiments. Cumulatively, the study by Professor Brugge and his colleagues is a very interesting preliminary work which warrants larger carefully controlled follow up studies.
References:
Brugge, D., Durant, J., & Rioux, C. (2007). Near-highway pollutants in motor vehicle exhaust: A review of epidemiologic evidence of cardiac and pulmonary health risks Environmental Health, 6 (1) DOI: 10.1186/1476-069X-6-23
Brugge, D., Lane, K., Stewart, A., Tai, A., & Woodin, M. (2013). Highway Proximity Associations with Blood Markers of Inflammation: Evidence for a Role for IL-1β Journal of Toxicology and Environmental Health, Part A, 76 (3), 201-205 DOI: 10.1080/15287394.2013.752325
