Toxicity effect of radiographic developer effluent on giant African snail (<i>Achatina fulica</i>)

Abstract

Background: The decline in the population of snails, a source of protein of people living in the high forest zone due to environmental pollution and the hazard caused by the disposal of radiographic developer effluent into streams, bushes or forests and public sewer systems makes the assessment of the effect on giant African snails (Achatina fulica) from environmental pollution due to radiographic developer effluent very important.
Materials and Methods: Ninety 5 months old, 12 months old and 24 months old giant African snails were randomly divided into 6 groups of 15 snails for each age group based on the dose of developer effluent to be administered. One group from each age group was designated the control and the remaining, the experimental group. Range finding test was performed at effluent concentrations of 100 %, 50 %, 25 %, 12.5 %, 6.25 %, 3.125 %, 1.6 % and 0 % (control) in 150 ml of distilled water. The effluent solution was administered on the feed and soil of the experimental snails only.
Results: Behavioural changes occurred between 0.2 – 1.0 % concentration and mortality at 24 – 96 hours exposure to the effluent solutions. The percentage (%) mortality of the giant African snails increased as the effluent concentration increased from 0.2 - 1.0 % and at increased exposure time of 24 – 96 hours. The estimated 96 hours LD₅₀ for the 5, 12 and 24 months old giant African snails were 0.20 0.23, 0.23 0.25 and 0.30 0.26 respectively.
Conclusion: Radiographic developer effluent is harmful to the giant African snails, with the % mortality increasing with increase in concentration and exposure time to the developer effluent. Legislation is recommended to ensure safe disposal of radiographic developer effluents into the Nigerian environment considering the importance of giant African snails (Achatina fulica) to the ecosystem and the economy.