Driving hazard - Vehicular emissions can affect your health

Eulalee Thompson

THE THICK, black smoke coming from the exhaust systems of poorly-maintained motor vehicles is actually the poisonous gas, carbon monoxide. This gas contributes to detoriation of urban air quality and when inhaled in high concentrations, it will not only cause ill-health but can kill.
The Health Ministry's environmental health section could offer no information on the grave public health risks of this gas and other vehicular emissions, but the National Environment and Planning Agency (NEPA), where The Gleaner was directed, had copious information.

In fact, Stephen Haughton, NEPA's senior director for Pollution Control and Waste Management, indicated that when carbon monoxide is absorbed into the blood stream, it reduces the oxygen-carrying capacity of the blood and will affect heart and lung functions.

Mobile sources also emit other gases and particulates. Mr. Haughton mentioned nitrogen oxides and volatile organic compounds (VOCs). He said that nitrogen oxides and VOCs in the presence of sunlight undergo photochemical and thermal reactions that result in the formation of photochemical smog.

The VOC emissions from mobile sources, he said, include several organic compounds such as benzene and 1,3-butadiene which have been described as carcinogens (or cancer-causing agents). Exposure to high concentrations of oxide of nitrogen (especially nitrous oxide and nitrogen dioxide have been linked to acute pulmonary oedema (that is, water in the lungs), bronchitis and broncho-pneumonia.

Mr. Haughton also points out that besides the gases, motor vehicle emissions also contain particulates which are tiny bits of solid matter. Particulate matter emissions from motor vehicles, he said, are in the range that easily enters the human respiratory tract. People with respiratory illnesses such as asthma and bronchitis might therefore be affected by pollutants from vehicles. Some of the chemical compounds in particulate matter are also considered toxic and carcinogenic.

The use of unlead gasolene is widespread in Jamaica now but where leaded gasolene is used, the particulate emissions will contain lead compounds which is toxic and have been linked to brain damage and gastrointestinal problems.

With all these potentially harmful gases and particulate, the contribution of motor vehicle pollutants to general ill-health should not be underestimated. NEPA points out that between 1993 and 1999, the fleet of motor vehicles on Jamaica's road has more than doubled moving from 171,000 to 348,000.

Contrary to what most people think, the transport sector is contributing heavily to the deterioration in the air quality. For example, the National Communication document (September 2000 by the Ministry of Water and Housing) indicates that the transport sector contributes 61.4 per cent of total carbon monoxide emissions compare to 22.2 per cent for the agricultural sector and 15.5 per cent for the residential and commercial sector. The contributions for the bauxite and electricity generation sectors were said to be negligible.

The transport sector also contributes 39.4 per cent of total nitrogen oxides emissions compare to 31.8 per cent for the bauxite sector and 18.3 per cent for the electricity generation sector.

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