Letter to the Editor
1
Letter to the Editor The recent paper by Craan and Haines (1998) sparked my interest because it provides scarce and greatly needed data on half-lives of organochlorines (OCs) in humans. The authors point out the steady decline of some, but not all, OCs in milk during the past 20–25 years. For DDT and TCDD, half-lives can be estimated from these Canadian data, and the results are remarkably similar to clearance times calculated using other population averages and individual data. Their average concen- trations in breast milk from 1975 forward give a half-life of 6.3 years for DDT (bis(4-chlorophenyl)-1,1,1—trichloroethane) residues (based on 6 time-points) and between 6 and 12 years for TCDD (2,3,7,8-tetrachlorodibenzodioxin; based on 2–3 time-points). Similar data from adipose tissue levels in the United States (Kutz et al. 1991; also plotted in Wolff 1995) provide a half-life estimate of 5.7 years for DDT residues (based on 10 or 11 annual mean values between 1970 and 1983). These half-life estimates agree with unpublished data from our laboratory on sequential measurements of DDE (bis(4-chlorophenyl)-1,1—dichloroethene, the primary residue of DDT) among approximately 400 individuals in two separate studies (manuscripts in preparation). Likewise, the TCDD half-lives in breast milk determined from the Canadian popula- tion means are consistent with several studies of exposed individuals, i.e., 7–10 years (Longnecker et al. 1997; Flesch- Janys et al. 1996). Peak DDT levels in Canadian adults, approximately 5000 ng/g lipid in 1967, were predicted by Craan and Haines to decline to 90 ng/g (parts per billion on a lipid basis) by the year 2001. The U.S. average in adipose tissue of greater than 10,000 ng/g DDT in 1967 (Kutz et al. 1991) should decline to 200 ng/g (ppb) by the next century. These findings may have public health and regulatory implica- tions and will be useful for epidemiologic studies that are measuring DDT. Mary S. Wolff Department of Community Medicine Environmental and Occupational Medicine Box 1057, 1 Gustave L. Levy Place Mount Sinai School of Medicine New York, New York 10029, U.S.A. References Craan AG, Haines DA (1998) Twenty-five years of surveillance for contaminants in human breast milk. Arch Environ Contam Toxicol 35:702–710 Flesch-Janys D, Becher H, Gurn P, Jung D, Konietzko J, Manz A, Papke O (1996) Elimination of polychlorinated dibenzo-p- dioxins and dibenzofurans in occupationally exposed persons. J Toxicol Environ Health 47:363–378 Longnecker MP, Rogan WJ, Lucier G (1997) The human health effects of DDT (dichlorodiphenyl-trichloroethane) and PCBs (polychlo- rinated biphenyls) and an overview of organochlorines in public health. Annu Rev Publ Health 18:211–244 Kutz FW, Wood PH, Bottimore DP (1991) Organochlorine pesticides and polychlorinated biphenyls in human adipose tissue. Rev Environ Contam Toxicol 120:1–82 Wolff MS (1995) Pesticides: how research has succeeded and failed in informing policy: DDT and the link with breast cancer. Environ Health Persp 103(Suppl 6):87–91 Arch. Environ. Contam. Toxicol. 36, 504 (1999) ARCHIVESOF E nvironmental Contamination and T oxicology r 1999 Springer-Verlag NewYork Inc.
Transcript of Letter to the Editor
Letter to the Editor
The recent paper by Craan and Haines (1998) sparked myinterest because it provides scarce and greatly needed data onhalf-lives of organochlorines (OCs) in humans. The authorspoint out the steady decline of some, but not all, OCs in milkduring the past 20–25 years. For DDT and TCDD, half-livescan be estimated from these Canadian data, and the results areremarkably similar to clearance times calculated using otherpopulation averages and individual data. Their average concen-trations in breast milk from 1975 forward give a half-life of 6.3years for DDT (bis(4-chlorophenyl)-1,1,1—trichloroethane)residues (based on 6 time-points) and between 6 and 12 yearsfor TCDD (2,3,7,8-tetrachlorodibenzodioxin; based on 2–3time-points). Similar data from adipose tissue levels in theUnited States (Kutzet al. 1991; also plotted in Wolff 1995)provide a half-life estimate of 5.7 years for DDT residues(based on 10 or 11 annual mean values between 1970 and1983). These half-life estimates agree with unpublished datafrom our laboratory on sequential measurements of DDE(bis(4-chlorophenyl)-1,1—dichloroethene, the primary residueof DDT) among approximately 400 individuals in two separatestudies (manuscripts in preparation). Likewise, the TCDDhalf-lives in breast milk determined from the Canadian popula-tion means are consistent with several studies of exposedindividuals, i.e., 7–10 years (Longneckeret al. 1997; Flesch-Janys et al. 1996). Peak DDT levels in Canadian adults,approximately 5000 ng/g lipid in 1967, were predicted byCraan and Haines to decline to 90 ng/g (parts per billion on alipid basis) by the year 2001. The U.S. average in adiposetissue of greater than 10,000 ng/g DDT in 1967 (Kutzet al.1991) should decline to 200 ng/g (ppb) by the next century.
These findings may have public health and regulatory implica-tions and will be useful for epidemiologic studies that aremeasuring DDT.
Mary S. WolffDepartment of Community MedicineEnvironmental and Occupational MedicineBox 1057, 1 Gustave L. Levy PlaceMount Sinai School of MedicineNew York, New York 10029, U.S.A.
References
Craan AG, Haines DA (1998) Twenty-five years of surveillance forcontaminants in human breast milk. Arch Environ ContamToxicol 35:702–710
Flesch-Janys D, Becher H, Gurn P, Jung D, Konietzko J, Manz A,Papke O (1996) Elimination of polychlorinated dibenzo-p-dioxins and dibenzofurans in occupationally exposed persons. JToxicol Environ Health 47:363–378
Longnecker MP, Rogan WJ, Lucier G (1997) The human health effectsof DDT (dichlorodiphenyl-trichloroethane) and PCBs (polychlo-rinated biphenyls) and an overview of organochlorines in publichealth. Annu Rev Publ Health 18:211–244
Kutz FW, Wood PH, Bottimore DP (1991) Organochlorine pesticidesand polychlorinated biphenyls in human adipose tissue. RevEnviron Contam Toxicol 120:1–82
Wolff MS (1995) Pesticides: how research has succeeded and failed ininforming policy: DDT and the link with breast cancer. EnvironHealth Persp 103(Suppl 6):87–91
Arch. Environ. Contam. Toxicol. 36, 504 (1999) A R C H I V E S O F
EnvironmentalContaminationa n d Toxicologyr 1999 Springer-Verlag New York Inc.
