Lead Toxicoses in Free-Range Chickens in Artisanal Gold-Mining Communities, Zamfara, Nigeria

Background: In early 2010, outbreaks of lead poisoning due to artisanal gold mining in villages in the northwest Nigerian state of Zamfara have resulted in the death of hundreds of children < 5 years old. There have also been unconfirmed reports of high mortality of geese within these villages.

Objectives: To report a case of lead poisoning in three domestic free-range chickens found in one of the affected communities where illegal small-scale gold mining activities take place.

Methods: Three free-range domestic chickens were presented during a field investigation in one of the villages. The birds were observed to be emaciated, weak, showing nervous manifestations and moribund.

Results: Tissue extracts of liver, spleen and intestines were negative for Newcastle viral antigens, while cultures of liver and spleen biopsy were positive for Escherichia coli. Histopathological lesions were observed in the kidney, proventriculus and brain. Concentrations of lead in the tissues ranged between 7.5 mg/kg and 120.5 mg/kg wet weight, and the potential daily intake of lead in the tissues were estimated at 34.06-200.15 μg/day/kg body weight with an average of 118.37 μg/day/kg body weight.

Conclusions: The results of the present study suggest probable risk to human health due to the consumption of chicken contaminated by lead in the affected villages. Poisoning in animal populations may serve as a sentinel to assess the extent of environmental contamination and human health problems related to lead.

Ethics approval: Protocols were approved and performed in accordance with relevant local guidelines and regulations as set by the Animal Care and Use Committee of the National Veterinary Research Institute, Vom, Nigeria.

Competing interests: The authors declare no competing financial interests.