Dr. Rahmat Awang
The Sun, May 23,1995
THERE ARE MYRIAD TOXIC AGENTS IN our environment; either from natural sources or industrial by-products.
These agents are found in the air, water, soil or even food; indoors or outdoors. They may produce adverse effects on a variety of living systems.
One example of contamination is air pollution. Common toxic agents in the air includes carbon monoxide, sulfur oxides, hydrocarbons, particulate matter, and nitrogen oxides.
Environmental pollution caused by these are man-made. The distribution of these toxic agents in the air depends on the distance and location (upwind versus downwind) from their sources. Acute exposure to toxic agents suspended in the air usually leads to irritation of the respiratory system.
Prolonged exposure could lead to diseases associated with inflammation of the bronchus, breathing difficulty and lung cancer.
Industrial wastes and fumes from cigarette smoking, open fire and leaded petrol continue to fill the environment. A bigger challenge emerges when chemical agents extremely resistant to natural decay processes, for example organochlorines, are involved.
These chemicals remain in the environment for many years. The accumulation of these agents will eventually influence the food chain process. In other words if we fail to take necessary measures to ensure the environment, health hazards are sure to be the aftermath. The Minamata tragedy is a classic example.
When faced with environmental contamination, a few logical considerations can assist in analysing the situation.
What is the nature of the toxic agents involved?
This question is posed in order to identify the potential hazard. It is important to know the agent, its chemical and physical properties, as well as its reactivity, flammability, explosiveness, or corrosiveness
How severe is the contamination?
This question is raised to assess the extent of damage that could result from the exposure. To answer this question, the concentration of the toxic agent in the soil, ground water and air needs to be measured. It may also be necessary to determine the present and future geographical situation to assess its severity.
If there is little likelihood of endangering lives, for example, the agent is non-toxic or only a very low toxin concentration is present in the environment, proper cleaning-up procedures are probably the only action needed.
On the other hand, if the concentration of toxin is high and dangerous to health, the following question should be asked. Are there people exposed to the toxic agent?
If there is no one living in the affected area, and it is not used for agricultural or relaxation purposes, there may not be potential health hazards even if the contamination is severe.
But, if the area involved is inhabited by people, several possible routes of exposure such as air or dust inhalation, ingestion through soil, dust, food or drinking water or skin contact soil, should be considered.
Hence, when dealing with such a situation, the following advice could help.
- Be ready to recognise the dangerous situation
- Respond appropriately by calling the necessary government authorities such as the Department of Environment, Department of Health, Hazmat Team, and the National Poison Centre.
These departments may be able to assess the full ramifications of the exposure and plan the necessary course of action to take.
In short, understanding the potential health hazard of agents in the environment should prompt us to be more concerned of our treatment towards it. The various incidents that were highlighted over the last few months (cyanide, sarin) should reinforce this concern.
