DDT a problem of 30-50 years ago?

[Paul Cherubini]

Joel Robert Lyons wrote:

> DDT persists in the environment for decades it is everywhere
> and in everybody. 

With what consequences to human health, Joel?

Gordon J. Edwards, a professor at California State
University, San Jose, CA has spent 30+ years studying the science
and politics of DDT. He has coauthored a website 
http://www.junkscience.com/ddtfaq.htm that lists 
"100 things you should know about DDT". Below I have copied and
pasted items #26-#38 that pertain to DDT and cancer:

Gordon prefaced this topic with the following statement:

"DDT WAS ALLEDGED TO BE A LIVER CARCINOGEN IN "SILENT 
SPRING" AND A BREST CARCINOGEN IN "OUR STOLEN FUTURE"  

26.Feeding primates more than 33,000 times the average daily human exposure
to DDT (as estimated in 1969 and 1972) was "inconclusive with respect to a
carcinogenic effect of DDT in nonhuman primates." 

[J Cancer Res Clin Oncol 1999;125(3-4):219-25] 

27.A nested case-control study was conducted to examine the association
between serum concentrations of DDE and PCBs and the development of
breast cancer up to 20 years later. Cases (n = 346) and controls (n = 346)
were selected from cohorts of women who donated blood in 1974, 1989, or
both, and were matched on age, race, menopausal status, and month and
year of blood donation. "Even after 20 years of follow-up, exposure to
relatively high concentrations of DDE or PCBs showed no evidence of
contributing to an increased risk of breast cancer." 

[Cancer Epidemiol Biomarkers Prev 1999 Jun;8(6):525-32]

28.To prospectively evaluate relationships of organochlorine pesticides and
PCBs with breast cancer, a case-control study nested in a cohort using the
Columbia, Missouri Breast Cancer Serum Bank. Women donated blood in
1977- 87, and during up to 9.5 years follow-up, 105 donors who met the
inclusion criteria for the current study were diagnosed with breast cancer.
For each case, two controls matched on age and date of blood collection
were selected. Five DDT analogs, 13 other organochlorine pesticides, and
27 PCBs were measured in serum. Results of this study do not support a
role for organochlorine pesticides and PCBs in breast cancer etiology. 

[Cancer Causes Control 1999 Feb;10(1):1-11]

29.A pooled analysis examined whether exposure to DDT was associated with
the risk of non-Hodgkin's lymphoma among male farmers. Data from three
case-control studies from four midwestern states in the United States
(Nebraska, Iowa, Minnesota, Kansas) were pooled to carry out analyses of
993 cases and 2918 controls. No strong consistent evidence was found for
an association between exposure to DDT and risk of non-Hodgkin's
lymphoma. 

[Occup Environ Med 1998 Aug;55(8):522-7]

30."We measured plasma levels of DDE and PCBs prospectively among 240
women who gave a blood sample in 1989 or 1990 and who were
subsequently given a diagnosis of breast cancer before June 1, 1992. We
compared these levels with those measured in matched control women in
whom breast cancer did not develop. Data on DDE were available for 236
pairs, and data on PCBs were available for 230 pairs. Our data do not
support the hypothesis that exposure to [DDT] and PCBs increases the risk
of breast cancer." 

[N Engl J Med 1997;337:1253-8] 

31."... weakly estrogenic organochlorine compounds such as PCBs, DDT,
and DDE are not a cause of breast cancer." 

[http://www.nejm.org/content/1997/0337/0018/1303.asp] 

32.To examine any possible links between exposure to DDE, the persistent
metabolite of the pesticide dicophane (DDT), and breast cancer, 265
postmenopausal women with breast cancer and 341 controls matched for
age and center were studied. Women with breast cancer had adipose DDE
concentrations 9.2% lower than control women. No increased risk of breast
cancer was found at higher concentrations. The odds ratio of breast cancer,
adjusted for age and center, for the highest versus the lowest fourth of DDE
distribution was 0.73 (95% confidence interval 0.44 to 1.21) and decreased
to 0.48 (0.25 to 0.95; P for trend = 0.02) after adjustment for body mass
index, age at first birth, and current alcohol drinking. Adjustment for other
risk factors did not materially affect these estimates. This study does not
support the hypothesis that DDE increases risk of breast cancer in
postmenopausal women in Europe. 

[BMJ 1997 Jul 12;315(7100):81-5]

33.No correlation at the population level can be demonstrated between
exposures to DDT and the incidence of cancer at any site. It is concluded
that DDT has had no significant impact on human cancer patterns and is
unlikely to be an important carcinogen for man at previous exposure levels,
within the statistical limitations of the data. 

[IARC Sci Publ 1985;(65):107-17]

34.Syrian golden hamsters were fed for their lifespan a diet containing 
0, 125, 250 and 500 parts per million (ppm) of DDT. The incidence of tumor
bearing animals was 13% among control females and ranged between
11-20% in treated females. In control males 8% had tumors. The incidence
of tumor bearing animals among treated males ranged between 17-28%. 

[Tumori 1982 Feb 28;68(1):5-10]

35.None of 35 workers heavily exposed to DDT (600 times the average U.S.
exposure for 9 to 19 years) developed cancer. 

[Laws, ER. 1967. Arch Env Health 15:766-775]

36.Men who voluntarily ingested 35 mgs of DDT daily for nearly two years
were carefully examined for years and "developed no adverse effects." 

[Hayes, W. 1956. JAMA 162:890-897]

37.DDT was found to reduce tumors in animals. 

[Laws, ER. 1971. Arch. Env Health, 23:181-184; McLean, AEM 
& EK McLean. 1967.Proc Nutr Soc 26;Okey, AB. 1972. Life Sciences 
11:833-843;Sillinskas, KC & AB Okey. 1975. J Natl Cancer Inst
55:653- 657, 1975]

38.Rodent tests for a carcinogenic effect of DDT, DDE and TDE produced
equivocal results despite extremely high doses (642 ppm of DDT, 3,295
ppm of TDE and 839 ppm of DDE). 

[National Toxicology Program, TR-131 Bioassays of DDT, TDE, 
and p,p'-DDE for Possible Carcinogenicity (CAS No. 50-29-3, CAS
No. 72-54-8, CAS No. 72-55-9)]