Original Article Organochlorines and Bone Mineral Density in Swedish Men from the General Population A. W. Glynn 1,2 , K. Michae¨lsson 3 , P. M. Lind 2 , A. Wolk 4 , M. Aune 5 , S. Atuma 5 , P. O. Darnerud 1 and H. Mallmin 3 1 Toxicology Division, Swedish National Food Administration, Uppsala; 2 Department of Environmental Toxicology, Uppsala University, Uppsala; 3 Department of Orthopaedics, University Hospital, Uppsala; 4 Deparment of Medical Epidemiology, Karolinska Institutet, Stockholm; and 5 Chemical Division 2, Swedish National Food Administration, Uppsala, Sweden Abstract. Persistent organochlorines (POCs), such as polychlorinated biphenyls (PCBs) and DDT, are present at relatively high concentrations in food and show estrogenic, anti-estrogenic or anti-androgenic activity in biological test systems. Because bone mineral density (BMD) in men is influenced by sex hormones, we looked for associations between BMD and serum concentrations of POCs in 115 men (mean age 63 years, range 40–75 years) from the general Swedish population. Ten PCB congeners, five DDT isomers, hexachlorobenzene, three hexachlorocyclohexane isomers, trans-nonachlor and oxychlordane were analyzed by gas chromatography. Quantitative bone measurements were performed by dual-energy X-ray absorptiometry at three sites: whole body, the L2–L4 region of the lumbar spine, and the neck region of the proximal femur, as well as by quantitative ultrasound on the left os calcis (broadband ultrasound attenuation (BUA) and speed of sound (SOS)). After adjustment for confounding factors in linear regression analyses we found no strong associa- tion between serum concentrations of single POCs and the five BMD and ultrasound variables. When POCs were grouped according to hormonal activity (estro- genic, anti-estrogenic, anti-androgenic) and the study subjects were divided into organochlorine concentration quartiles, a weak association was indicated between increased serum concentrations of p,p’-DDE (anti- androgenic) and decreased BMD, BUA and SOS. This may suggest that p,p’-DDE could cause negative effects on bone density, but the findings might also be due to chance since multiple comparisons were made in the statistical analysis. Overall our results do not suggest that the studied POCs caused major effects on bone density in our study group. Keywords: Bone mineral density; DDE; DDT; Endo- crine disrupters; PCB Introduction Persistent organochlorines (POCs), such as the industrial chemical polychlorinated biphenyl (PCB) and the chlorinated pesticide DDT, are ubiquitous in the environment even though the production and use of these chemicals have been banned for decades in many countries. Although the concentrations of these com- pounds in food have slowly decreased in some areas of the world, concentrations are still high enough to be of concern for human health [1]. PCB and chlorinated pesticides cause a variety of endocrine effects in biological test systems, including estrogenic, anti-estrogenic and anti-androgenic effects [2,3]. Experimental studies show that these effects may be caused by several mechanisms, including direct binding of the compounds to estrogen and androgen receptors and effects on activities of sex-hormone- metabolizing enzymes such as aromatase [1]. On the basis of these findings it has been hypothesized that background exposure to POCs in food may induce reproductive effects in humans [4]. Osteoporos Int (2000) 11:1036–1042 ß 2000 International Osteoporosis Foundation and National Osteoporosis Foundation Osteoporosis International Correspondence and offprint requests to: Anders Wicklund Glynn, Toxicology Division, Swedish National Food Administration, PO Box 622, SE 751 26 Uppsala, Sweden.