Acute and subchronic toxicity of lead to the spotted babylon, Babylonia areolata (Neogastropoda, Buccinidae)

Abstract

The acute and subchronic toxicity of lead was determined in the spotted babylon, Babylonia areolata. The 96-h static bioassay was conducted to estimate the median lethal concentration (LC50). The snails were exposed to lead nitrate (Pb[NO3]2). The LC50values for 24, 48, 72, and 96 h were 29.31, 14.64, 12.44, and 10.50 mg Pb/L, respectively. In the subchronic experiment, the snails were exposed to 0.5 mg Pb/L (10% MATC, the maximum acceptable toxicant concentration) of lead nitrate for 3 mo. Lead accumulation was found in different organs with the greatest accumulation in the stomach and lesser in the esophagus, gill, rectum, digestive gland, proboscis, and foot. The histopathologic alterations in the digestive system and gills of B. areolata were studied by light microscopy. The general tissue alterations were decrease in length of cilia, decrease in acidophilic granules, slight distension of nuclei, and the loss of heterochromation. There were increases of mucous vacuoles, damaged ciliated cells, and enlargement of vacuoles.