Environmental pollution and its impact on domestic animals and wildlife

Environmental pollution is a major global problem posing serious risk to man and animals. It is defined as the human alteration of chemical or physical characteristics of the environment to a degree that is harmful to living organisms. Rapid pace of urbanization, industrialization and indiscriminate and improper use of chemicals such as pesticides and drugs have resulted in increased contamination and degradation of the environment leading to adverse health effects on living beings and problems associated with residues in food of animal origin. Recent emergences in environmental related toxicity in man and animals and detection of chemical residues in food products at an increasing frequency have underlined the impact of pollution on biotic component. The deleterious health effects may be observed in the form of overt clinical signs and higher morbidity and mortality or as subtle or subclinical effects. Pesticide toxicity, plumbism, mercury poisoning and fluorosis are some of the commonly encountered overt toxic problems due to pollution in domestic animals. The low level of exposure to pollutants is often associated with chemical residues in animal system, and subtle or subclinical effects. These include oxidative stress, immunotoxicity, carcinogenicity, teratogenecity and endocrine disruption. Wild animals, like their domestic counterparts also suffer from adverse effects of pollution. Eggshell thinning in birds of prey due to DDT residues and heavy mortality amongst fish and birds due to contamination of aquatic ecosystem with mercury, oil spills or acid rains are some of the notable examples of impact of pollution on wild life.. Recently, decline in vulture population in Indian subcontinent has been linked to drug residues. This has drawn the attention of researchers and environmentalist owing to drastic decline in the population of an important raptorial bird species and resultant ecological degradation. Besides deleterious health effects on animal and wildlife, chemical pollutants also pose public health concerns because of contamination of human food chain. Noise and other physical pollutants are also reported to cause adverse effects on health and physiology. This review describes the incidence, source of pollutants, adverse health effects and scientific achievements in the field of environmental pollution with particular reference to animal and wildlife health.