title: Comparative toxicity of tetra ethyl lead and lead oxide to earthworms, Eisenia fetida (Savigny).
abstract: Leaded gasoline contains tetra ethyl lead (TEL) as an antiknocking agent, which produces major amounts of lead oxide in automobile exhaust along with traces of TEL. To minimize the lead contamination, methyl tertiary butyl ether (MTBE) is used as a substitute for producing unleaded gasoline. It has become increasingly apparent that young children are highly susceptible to the harmful effects of lead. Hence, a study was carried out to monitor lead toxicity in soil, using adult earthworms (Eisenia fetida, Savigny). Leaded gasoline (TEL) and lead oxide are 383- and 211-fold more toxic than unleaded gasoline (MTBE) in 7 days of exposure and 627- and 290-fold more toxic in 14 days, respectively. Results indicate that the presence of TEL in leaded gasoline and lead oxide has a significant effect on behavior, morphology, and histopathology of earthworms. Absorption of TEL into the tissues is comparatively less than that of lead oxide but toxic effects were severe. Rupture of the cuticle, extrusion of coelomic fluid and inflexible metameric segmentation were observed, causing desensitization of the posterior region leading to fragmentation in earthworms.
authors.affiliation: Toxicology Unit, Biology Division, Indian Institute of Chemical Technology, 500 007, Hyderabad, India. jv@iict.ap.nic.in
authors.forename: J
authors.initials: J
authors.lastname: Venkateswara Rao
authors.forename: P
authors.initials: P
authors.lastname: Kavitha
authors.forename: A
authors.initials: A
authors.lastname: Padmanabha Rao
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods; D005742:Gasoline / Q000633:toxicity; D007854:Lead / Q000493:pharmacokinetics / Q000633:toxicity*; D007928:Lethal Dose 50; D008738:Methyl Ethers / Q000493:pharmacokinetics / Q000633:toxicity; D009835:Oligochaeta / Q000187:drug effects* / Q000378:metabolism; D010087:Oxides / Q000493:pharmacokinetics / Q000633:toxicity*; D012989:Soil Pollutants / Q000633:toxicity*; D013756:Tetraethyl Lead / Q000493:pharmacokinetics / Q000633:toxicity*; D014018:Tissue Distribution
chemical_list: D005742:Gasoline; D008738:Methyl Ethers; D010087:Oxides; D012989:Soil Pollutants; D013756:Tetraethyl Lead; C043243:methyl tert-butyl ether; D007854:Lead; C047365:lead oxide