Clarence A. Haule
For a town or city dweller, it is a common thing to see smoke billows from vehicles’ exhaust pipes. That is the biggest evidence to the naked eye that automobiles are big contributors to air pollution. In major cities and large towns throughout the world, automobiles cause a wide range of air pollution problems.
When vehicles and other automobiles burn fuel, they emit pollutants. Fumes escape into the air even when we pump gasoline into our fuel tanks. This makes automobiles major contributors to air pollution. In the US, according to the U.S. Environmental Protection Agency, more than half of the air pollution is caused by mobile sources, primarily automobiles.
Air pollution is the introduction of chemicals, particulates, biological materials or other harmful materials into the Earth’s atmosphere, possibly causing diseases, death to humans, damage to other living organisms or the natural or built environment. The atmosphere is a complex natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth’s ecosystems.
There are various locations, activities or factors which are responsible for releasing pollutants into the atmosphere, automobiles being one of them. Of recent we have experienced a growing number of vehicles imported in Tanzania as a result of the fast growing economic activities in the country. Statistics show that the number of vehicles imported through Dar es Salaam port per day is approximately 100 vehicles (TBS). This is quite a large number of vehicles which should trigger attention on pollution.
Air pollution is a significant risk factor for multiple health conditions including respiratory infections, heart disease, and lung cancer, according to the World Health Organization (WHO). The health effects caused by air pollution may include difficulty in breathing, wheezing, coughing, asthma and aggravation of existing respiratory and cardiac conditions. These effects can result in increased medication use, increased doctor or emergency room visits, more hospital admissions and premature death.
The human health effects of poor air quality are far reaching, but air pollution principally affect the body’s respiratory system and the cardiovascular system. Individual reactions to air pollutants depend on the type of pollutant a person is exposed to, the degree of exposure, the individual’s health status and genetics. The most common sources of air pollution include particulates, ozone, nitrogen dioxide, and sulfur dioxide. Both indoor and outdoor air pollution have caused approximately 3.3 million deaths worldwide. Children aged less than five years that live in developing countries are the most vulnerable population in terms of total deaths attributable to indoor and outdoor air pollution.
Currently, authorities worldwide are working hard to ensure that the environment is well protected from pollution. At the national level, Tanzania Bureau of Standards (TBS) is among those at the forefront in setting up requirements that help curb pollution caused by automobiles. For example the formulation of Tanzania standards number TZS 983:2007 and TZS 698:2007 was aimed at fighting against, among other things, uncontrolled environmental pollution caused by automobiles. TBS being a national standards body uses these standards to inspect all vehicles imported to our country to check if they are roadworthy and environmentally friendly before they are allowed into our environment.
TZS 983:2007, Air quality – Vehicular exhaust emissions limits gives permissible limits of some common substances found in exhaust emissions of motor vehicles, namely carbon monoxides, suspended particulate matter (PM), oxides of nitrogen, and hydrocarbons. The standard covers all types of vehicles, namely passenger cars, light commercial vehicles, heavy-duty vehicles, and two and four strokes motorcycles and scooters. On the other hand, TZS 698:2012, Road vehicles – Code of practice for inspection and testing of used motor vehicles for road worthiness specifies the safety related performance characteristics of used motor vehicles and their inspection and tests for roadworthiness.
However, in matters of controlling emissions that may adversely affect the environment, inspection is one thing and maintaining emission levels is quite another. For example, one may ask, do all vehicles on the road maintain emission limits? Definitely the answer is no, as for the time being Tanzania does not have regulations that require every vehicle on the road to be tested regularly after TBS has done its part on their entry in our country. In a different scenario, we might have the regulations in place but no enforcement.
Nevertheless, we cannot sit aside and watch as automobiles pollute our environment. The government in collaboration with its stakeholders needs to establish a mechanism by which all the vehicles on the road will have to undergo tests annually to check if they still maintain emission standards. This may be achieved by appointing and certifying agents (garages) whose task will be to carryout testing activities on behalf of the government and upon passing the test, the vehicle will be granted roadworthiness certificate and subsequently the road licence.
*Clarence Haule is a Quality Assurance Officer in the Mechanical Engineering Laboratory