Organochlorine pesticides in commercial marine fishes of Coimbatore, India and their suitability for human consumption Subramaniyan Muralidharan à , Venugopal Dhananjayan, Palaniyappan Jayanthi Ecotoxicology Division, Sa ´lim Ali Centre for Ornithology and Natural History, Coimbatore 641 108, TN, India article info Article history: Received 31 August 2007 Received in revised form 4 June 2008 Accepted 11 August 2008 Available online 11 October 2008 Keywords: Marine fishes Organochlorine pesticides MRLs Human consumption Dietary intake abstract Organochlorine pesticide residues were determined in 10 species of fishes caught at Cochin and Rameshwaram coast, and sold in Coimbatore, Tamil Nadu, India. Species were selected on the basis of their regular availability throughout the year and commercial value. A total of 389 fishes were analyzed for organochlorine residues and their suitability for human consumption was evaluated. Results show varying levels of residues of hexachlorocyclohexane (HCH), DDT, heptachlor epoxide, endosulfan and dieldrin. Among the 10 species, high concentration of pesticide residues were recorded in Sardinella longiceps, Carangoides malabaricus, Chlorophthalmus agassizi, Saurida tumbil and Rastrelliger kanagurta. The variation in total organochlorine residues among species and between places was not significant (P40.05). Only five species of fishes showed monthly variation in residue levels and there was no significant correlation between the body size and residue levels in the tissue. About 22% of the fishes exceeded the maximum residue limits (MRL) of total HCH prescribed by FAO/WHO for fish products. The calculated dietary intake of total HCH through consumption of C. malabaricus, C. agassizi and S. longiceps exceeded the maximum acceptable dietary intake (ADI) limits prescribed for human consumption. The present study recommends continuous monitoring of environmental contaminants in marine fishes to assess the possible impact on human health. & 2008 Elsevier Inc. All rights reserved. 1. Introduction Organochlorines continue to be the potential group of chemicals used in control of agricultural pests and vectors of diseases like malaria (David et al., 2003), even though many new broad spectrum pesticides have been developed in recent years. Moreover, the lipophilic nature, hydrophobicity and, low chemical and biological degradation rates of organochlorine pesticides have led to their accumulation in biological tissues and subsequent magnification of concentration in organisms progressing up in the food chain (Swackhamer and Hites, 1988). Pollution by persistent chemicals is potentially harmful to the organisms at higher trophic levels in the food chain. The aquatic organisms like fish are able to accumulate several fold higher concentration of pesticide residues than the surrounding water (Siddiqui et al., 2005). It has been found that greater than 80% of the total intake of pesticide residues in human beings is through the food chain (Martinez et al., 1997; Trotter and Dickerson, 1993). Studies have also related the presence of organochlorine residues in breast milk and consumption of contaminated fish, and their role in alteration of thyroid function (Fitzgerald et al., 2001; Hagmar et al., 2001). It has been reported that considerable amount of organochlorine pesticide residues find their way into humans through consump- tion of contaminated marine fishes (Mwevura et al., 2002). India is now both the largest manufacturer and consumer of pesticides in South Asia. Despite the proliferation of different types of pesticides, organochlorines such as hexachlorocyclohex- ane (HCH) and DDT still account for two-thirds of the total consumption in the country (Kumari et al., 2001) for agriculture and public health purposes. Due to the human and environmental risks associated with the use of such pesticides, they have been banned in several countries but are still used in India (Mathew, 1993). In India as most of the rivers pass through agricultural fields, they are subjected to contamination with different pesticides used for crop protection. Higher levels of HCH are being reported to occur in Indian marine waters and it is estimated that about 25 tonnes of organochlorines produced have been already transported to the sea (Mohapatra and Saha, 2000). In India there are many studies on the presence of organo- chlorine residues in aquatic system; water and fishes (Sarkar et al., 2003), soil and ground water (Singh, 2001), water (Muralidharan, 2000) and water, sediment and fishes (Vijayan and Muralidharan, 1999). Studies done by Kole et al. (2001) reported the presence of endosulfan and HCH residues in fishes sold at Calcutta market. Karunagaran et al. (1994) documented the presence of ARTICLE IN PRESS Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/envres Environmental Research 0013-9351/$ -see front matter & 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.envres.2008.08.006 à Corresponding author. Fax: +91422 2657088. E-mail address: ecot_mur@yahoo.com (S. Muralidharan). Environmental Research 109 (2009) 15–21