Pesticides are the only hazardous substances that are intentionally discharged in a significant amount into the environment. The accumulation of these contaminants in different body organs, eggs, and prey samples of avian species has been reported worldwide. Carbamates, organophosphates, and organochlorines are commonly used pesticides.
Organophosphates have been used extensively as pesticides for forty years and form an important category of pesticides. Organophosphates are generally known for their neurotoxic effects, particularly in insects, but they also induce other conditions, including rhabdomyopathy, delayed neuropathy, immunotoxicity, and teratogenicity. Carbofuran belongs to the anticholinesterase carbamate group and commonly being practiced in the agriculture sector. Due to its widespread use in agriculture, water, air, and food is being contaminated, resulting in an adverse impact on humans, the wild, and the aquatic ecosystem. Currently, carbofuran is primarily involved in malicious poisoning. We conducted an experiment in which 150 eggs were collected from different nests (50 eggs/breeding heronry) located in Kot Hara Punjabi, Gondlanwala, and the Daska region of Punjab. Also, 200 cattle egrets were reared for six months at experimental units of the university of veterinary and animal sciences, Ravi Campus, Pattoki.
The birds were divided into seven groups; group A: captured from Kot Hara Punjabi, group B: captured from Gondlanwala, group C: captured from Daska, group D: carbofuran treated (0.03 mg/L), group E: carbofuran treated (0.02 mg/L), group F: carbofuran treated (0.01 mg/L), group G: non-exposed to any pesticide (negative control). Parameters including drug residue analysis, hematology, serum biochemistry profile analysis, immune response detection through cytokines analysis, egg quality parameters, micrometry of immune organ, and histopathological analysis of immune organs.
It was investigated that carbofuran exposure to cattle egret may result in hemolysis of red blood cells, decreased packed cell volume, increased mean corpuscular volume and mean corpuscular hemoglobin, and decreased mean corpuscular hemoglobin concentration, leukocytosis, lymphopenia, eosinophilia, and increased heterophils (%), increased liver and renal parameters, decreased interferon-gamma and interleukin two levels, decrease in egg quality parameters, atrophy of bursa of Fabricius, spleen, and thymus accompanied by microscopic lesion induced in immune organs such as congestion, hemorrhages, necrosis, and atrophy. It can be concluded from the present study that carbofuran exposure to wild birds like cattle egrets has a potentially adverse impact on their health.
Therefore, the wide use of carbofuran in the agricultural sector should be discouraged to mitigate the drastic changes in the ecosystem.
DR KHALID MAHMOOD ANJUM