Diesel exhaust fumes health and safety issues have been pushed to the forefront of health news by passage of new U.S. governmental regulations pertaining to railroad locomotive engines and other diesel spewing engines, as well as publication of a number of diesel exhaust fume studies, which showed that prolonged exposure caused “diesel asthma” and also are linked to increased incidence of lung cancer.
One of the leading authorities on the health and safety dangers of diesel exhaust fumes is Dr. Dick Van Steenis, a specialist in occupational medicine and scholar, who lives in Great Britain. After the exchange of email discussions with Dr. van Steenis on current topics of interest relating to diesel fumes, I thought it would be a great idea to interview him on this important health and safety topic. The interview follows:
Q: For those persons in the United States reading this article, I wanted to first note that you are actually a resident of England and are also a medical doctor by background and training. Can you tell us briefly about your medical career and how you became interested in health issues relating to diesel exhaust fumes?
A: I have been researching the health effects of industrial air pollution for 13 years. I used to be a general medical practitioner and in 1995 was asked by the Campaign for the Protection of Rural Wales to sort out health aspects of a power company application. I clearly needed to learn the subject and was in contact with leading experts located at Harvard, Denver & elsewhere, and extensively read and studied this subject over many years. I am now published in 4 medical publications & have lectured at 4 international medical conferences including 2 in USA (Dallas & Hot Springs).
Q: Tell us about some of the adverse health effects of diesel exhaust fumes you have studied in the United Kingdom?
A: My research includes effects of emissions from using various qualities of diesel ranging from “city diesel” which is between road diesel & kerosene, down to dirty industrial diesel mixes including waste oils with solvents. Diesel quality in trains in the UK varies with each company. Virgin are cleanest & First Great Western worst. The particulates emitted from diesel finally become PM1 to PM2 in size and contain carbon, polyaromatic hydrocarbons, other items and in the case of waste oil mixes also heavy metals. Carbon monoxide, carbon dioxide and nitrogen oxides are also emitted. Inhalation of carbon monoxide is not healthy, nor is inhalation of particulates of the PM1 to PM2.5 size all of which go into the depths of your lungs.
Q: Here in the United States, diesel fuel is not used with nearly the frequency it is in Great Britain or Europe as virtually 99% of the automobiles in this country use gasoline and not diesel. Based on your research what would you consider the worst polluters of diesel exhaust fumes in the United States and is this the same in Great Britain?
A: The worst polluters in the UK are earth moving equipment. One such machine was tested using industrial diesel and emitted as many fine particulates as 900,000 Volvo V70 cars and most were of the PM1 size. Four “bulldozers” working on a development in Brighton (UK) June 2007 caused air levels as high as 1100ug/m3 (safe level about 5ug/m3). The second worst emitters are some trains of old technology using inferior quality diesel fuel. (I am only discussing diesel vehicles, not oil refineries or incinerators, which have huge health effects in the UK).
Q: Based on your research, is there a clear consensus as to what part of diesel exhaust fumes are likely causing the increased lung cancer rates that have been studied and analyzed?
A: Lung cancer can be caused by polyaromatic hydrocarbons always present in diesel emissions, and by any heavy metals present such as nickel, cadmium or chromium.
Q: In one of our email exchanges you explained that particulate size (PM)of diesel exhaust fumes is a very important medical and health factor in relation to disease process in the lung. Can you please explain this so it is easily understood for a reader?
A: When PM1 & PM2.5 diesel emissions are inhaled, the soluble content goes into the blood stream. The rest is dealt with by macrophages and T-lymphocytes of the immune system. That leaves the body unprotected against infections and vaccines as the T-lymphocytes are busy in the lungs. The remnants of the particles are walled off by fibrous tissue causing COPD. The reaction sets up an inflammation causing platelets & red cells to become more sticky which can lead to a heart attack. Any nickel present messes up the heart’s electrical system. Other content alters the blood cholesterol making it more dangerous.
Q: Is diesel fuel sold in the United States now, since the year 2000, essentially the same as diesel fuel that was sold in the 1970s and 1980s as far as pollution or health effects?
A: The quality of road diesel sold in USA & UK has improved since 1990 and of non road diesel it has improved in USA due to the USEPA stipulating reductions of sulphur content by 99%. Further improvements can only be made in purity & viscosity.
Q: Thanks very much for agreeing to this interview!
A: You are very welcome.