Lead poisoning of horses in the vicinity of a battery recycling plant.

This research investigates the cases of lead poisoning in horses living near a battery recycling plant, finding high lead levels in soil, vegetation, and the horses themselves, which exceeded lethal levels.

Methodology

• The researchers diagnosed lead poisoning in horses based on clinical signs and laboratory findings. They collected samples from six horses, analyzing blood, liver, and kidney tissues for lead concentrations.
• They also collected samples of surface soil (0-15 cm depth) and herbage (plant material) from different distances to the recycling plant. This helped determine the lead distribution pattern in the environment surrounding the facility.
• The research team additionally undertook a water washing pre-treatment on the vegetation samples to check if airborne lead particles from the facility emissions were responsible for the high lead concentration in plants.

Key Findings

• Chemical analysis of the soil and herbage samples uncovered very high total lead levels near the recycling plant, which decreased as distance from the facility increased.
• Lead concentrations in the soil ranged from 127 to 5657 mg per kg, with more than 70% of lead extractable by the chelating agent EDTA in the most polluted soils.
• The lead levels in the aerial part of herbage samples ranged from 113 mg to 4741 mg per kg. The water washing pre-treatment substantially lessened the lead concentration in the plant samples, indicating that the lead was mainly airborne particle deposits from the recycling plant’s emissions.
• The examinations of the deceased horses revealed average lead concentrations of 0.20-0.89 mg per kg (d.w.) in their blood, 2.5-15 mg per kg in their livers, and 1.70-6.75 mg per kg in their kidneys.
• According to the estimated ingestion rate of Grammineae (grass family) forage, a horse living closest to the recycling plant would consume about 99.5 mg of lead per kg body weight per day. This is significantly higher than the lethal dose of 2.4 mg of lead per kg body weight per day as previously reported in scientific literature.

Conclusion

• The research concludes that horses living near the battery recycling plant were exposed to dangerous levels of lead, primarily through the ingestion of contaminated vegetation.
• The findings underscore the severe threat that battery recycling facilities pose to local agricultural ecosystems and wildlife, particularly when adequate emission containment measures aren’t in place.