Inadvertent exposure to organochlorine pesticides DDT and derivatives in people from the Canary Islands (Spain) Manuel Zumbado a,b , Muriel Goethals a,b , Eva E. A ´ lvarez-Leo ´n b,c , Octavio P. Luzardo a,b , Fe ´lix Cabrera a,b , Lluis Serra-Majem b,c,d , Luis Domı ´nguez-Boada a,b, * a Toxicology Unit, Department of Clinical Sciences, University of Las Palmas de Gran Canaria, P.O. Box 550, 35080, Las Palmas de Gran Canaria, Spain b Instituto Canario de Investigacio ´n del Ca ´ ncer (ICIC), Spain c Preventive Medicine Service, Complejo Hospitalario Materno Insular de Gran Canaria, Canary Health Service, Avda. Marı ´tima s/n, 35016, Las Palmas de Gran Canaria, Spain d Preventive Medicine and Public Health Unit, Department of Clinical Sciences, University of Las Palmas de Gran Canaria, P.O. Box 550, 35080, Las Palmas de Gran Canaria, Spain Received 22 March 2004; accepted 22 July 2004 Abstract In 1998, one of the largest determinations of organochlorine pesticides in a representative sample of a Spanish population (682 serum samples from the Canary Islands) was made in the context of the bCanary Islands Nutrition SurveyQ (ENCA). In the Canary Islands, extensive farming areas have been developed in these last decades, with greenhouses dedicated to intensive cultivation using DDT in huge amounts. In Spain, similarly to other European countries, DDT was banned in the late 1970s. The pesticide residues in human serum are indicative of past and present exposure to them. Our objective is to point out the differences of pesticide contamination between islands; and together with this, if a connection could be established with gender, age, or habitat of subjects. Concentration of selected persistent organochlorine pollutants ( p , p V -DDT, o , p V -DDT, p , p V -DDE, o , p V -DDE, p , p V -DDD, and o, p V -DDD) was measured with gas chromatography-electron capture detector. Almost all of the samples (99.3%) presented detectable levels of some DDT-derivatives, being p ,pV -DDE the most frequently detected organochlorine. The median concentration of total DDT body burden, expressed in ng/g fat, present in the Canary Islands (370 ng/g fat) was similar to that found in other European countries, although it was noteworthy that a fourth of the population showed a total DDT body burden higher than 715 ng/g. Interestingly, statistical significant differences were found in serum levels of organochlorine pesticides between islands, being these levels higher in people from Tenerife and Gran Canaria (415 and 612 ng/g fat, respectively), the islands that present both highest population and highest surface devoted to intensive agriculture. As expected, serum levels of both total DDT body burden and p , p V -DDE increased with age. Statistically significant differences were also found in relation to gender, women showing higher levels of these organochlorine pesticides 0048-9697/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.scitotenv.2004.07.022 * Corresponding author. Toxicology Unit, Department of Clinical Sciences, University of Las Palmas de Gran Canaria, P.O. Box 550, 35080, Las Palmas de Gran Canaria, Spain. Tel.: +34 928 453 472; fax: 34 928 451 416. E-mail address: ldominguez@dcc.ulpgc.es (L. Domı ´nguez-Boada). Science of the Total Environment 339 (2005) 49– 62 www.elsevier.com/locate/scitotenv