There appears to be three main areas of concern related to acid rain. Its effects on the air we breathe, the water we drink, and the food we eat.
i) Elder (1992) states that acid rain has not been observed to pose any external concerns to humans, but acidic airborne pollutants in gaseous forms such as the oxides of sulphur and nitrogen may lead to the irritation of the respiratory tract and subsequent impaired lung function, aggravated asthma, and bronchitis when inhaled. In an Environment Canada Report (1999), it is sighted that pollutants resulting from sulphur dioxide and nitrogen dioxide emissions can have significant effects on human health, ranging from eye, nose and throat irritation to the reduction of lung capacity, aggravation of respiratory diseases and even premature death.
A study as early as 1970 in the "Air Pollution Control Association Journal" concluded that children living in areas of high exposure areas to suspended NO2 particulates showed higher incidences of respiratory illnesses than children living in moderate levels or control sites.
ii) The leaching of toxic chemicals from watersheds and from water storage systems leads to the contamination of drinking supplies. A study by the Ministry of the Environment (1988), found that drinking water samples from acid lakes in Muskoka - Haliburton had elevated levels of metal (aluminum, lead and copper) when water had been standing in pipes for a few hours or overnight. Drinking of this water could cause ing or even metal poisoning.
iii) The contamination of edible fish by toxic chemicals, principally mercury and aluminum is also a concern. There is evidence to suggest that the fish populations in poorly buffered waters with lower pH have elevated levels of chemicals in their tissues. Humans who eat large quantities of such contaminated fish may be at great risk from chemical poisoning. Mercury can accumulate in the human body and cause irreversible nerve damage and possible death. A report by a Canadian Government Sub-Committee on Acid Rain (1981), concluded that there is sufficient concern about the dangers associated with acid rain and fish contamination to warrant concentrated research and public health monitoring programs.