EFFECTS OF AIR-POLLUTION ON RESPIRATORY SYSTEM .1. AMMONIA

Ammonia is often detected in animal houses at concentrations which can induce toxic effects. At first, this gas is absorbed at the level of the upper airways but is able to reach the lung directly or after absorption on particles. Short-term exposure can reduce the defence mechanisms of the respiratory tract against microbiological agents or can induce after-effects at the level of airways. The most obvious effects after long-term exposure is the sensitization of animals to respiratory diseases. Ammonia toxicity seems also be enhanced by combination with other chemical, physical or biological factors. These phenomena have received little attention so far and make it difficult to establish the no-adverse effect level of exposure.