Is diesel pollution suffocating our hearts?

Is diesel pollution suffocating our hearts?

In a recent study at the University of Edinburgh, researchers found new connections between polluting diesel fumes emanating from city vehicles and the incidence of heart impairments, indicating blood vessel activity gone haywire.

The repertoire of existent research has depicted a hazy bridge between fatal heart ailments, or intense hospitalization due to strokes, and the density of vehicular pollution. The trends shown are strongest in the case of fine pollution, resulting from the use of fossil based fuels. Still, the detailed analysis of this linkage between pollution and blood vessel impairment is largely unexplored.

The study conducted by Dr. Nicholas Mills, from the University of Edinburgh's Centre for Cardiovascular Science, comes as a step ahead in this direction, building further on what is already known.

In a nutshell, the research team found that exposure to diesel fumes for an hour during exercising affected a substantial decrease in the blood vessels' capacity to dilate. The same exposure additionally lowered levels of an enzyme which is instrumental in stalling clotting of blood in arteries and thus preventing heart attacks.

The study subjects were a group of 30 healthy men, non-smoking and in the age group 20-38, who underwent two one-hour tests, at an interval of two weeks.

In each testing round, the subjects were divided into random groups, one exposed to filtered air and the other to diesel fumes as they did some stationary cycling in 15 minute time spans inside a specially designed diesel exposure room. Diesel fumes were produced from an idly running engine and the concentration of fumes was likened to side street exposure in a big city on a busy day.

Two hours after being in the chamber, each subject was injected with a blood vessel dilating drug in one forearm. The team then measured blood flow in the injected and non-injected arms, comparing it to blood flow measured before the experiment.

The readings taken two hours and six hours after exposure to filtered and diesel air indicated that the dilating drugs caused increased blood flow after exposure to both types of air. But in diesel exposure, the blood flow dropped lower to that of the filtered air group. The reading was even milder after six hours of diesel exposure, showing higher clotting levels.

In short, the experimental conditions were a kind of simulation of real life exposure to diesel pollution in life, when walking on the pavement or cycling or sitting and getting exposed to fumes. The inferences drawn showed that low levels of diesel pollution can act as a propeller towards a heart attack. Exposure for a short period may aggravate existing problems and cascade to hospitalization for heart or lung impairments. A longer period of exposure can be purely fatal. Dr. Mills says that longer exposure can definitely contribute to the onset of coronary artery disease specifically.

According to Dr. Russell V. Luepker, a spokesperson for the American Heart Association, this study shows that if science attempts to look for significant connections, it can eventually find them for everything.

The findings have high potential for the U.S. Environmental Protection Agency. The agency is at present funding a program to attach diesel-using vehicles with specially designed devices that aid the trapping of fine particles in diesel fumes. However, it does need to ascertain first whether particles emanating from a combustive process are the real culprits in causing pollution and illnesses.

Whether the results of the study are similarly applicable to fuels like gasoline, is not clear yet, as their fumes are markedly different from diesel ones. Diesel is known to be a more heavy pollutant than gasoline, and diesel using vehicles are on the rise these days, thus initiating the main interest for the Edinburgh study.

Dr. Mills is of the opinion that the study is a stepping stone to further research required on the subject. Dr. Luepker also felt that since the controls in the experiment were near perfect, the findings make for "interesting initial data."