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July 2003. Research links herbicides used on wheat to birth defects in the Great Plains. A scientist from the US EPA finds that birth defects of several types are more common in babies born in wheat growing counties in the Great Plains, compared to rural counties in the same region where wheat is less common. Taken together with a wealth of data from others studies of people and experiments with rodents, this work strengthens the theory that chlorophenoxy herbicides like 2,4-D cause birth defects in people. More... Falling rate of non-Hodgkin's lymphoma in Sweden and US may be due to decreased chemical exposures. Two Swedish scientific experts on the epidemiology of non-Hodgkin's lymphoma (NHL) propose that recent declines in the incidence of this cancer may be a result of bans and restrictions on certain chemicals that began to take effect in the 1970s. Their theory rests on research consistently finding links between these chemicals and NHL, and reductions in exposures to the chemicals that now are clearly evident in body burden measurements. If true, this is one cancer on which we are starting to win the war for prevention. 4 July 2003. More... Women exposed in the womb to DDT have more difficulty becoming pregnant. Research published in the Lancet reports a strong association between levels of DDT in a mother's blood at the time she gave birth to a daughter, and 'time to pregnancy' in the daughter, 30 years later. The longer the 'time to pregnancy,' the more likely a women is to experience impaired fertility. The study took advantage of serum samples stored in freezers since drawn, 1960-1963, linking them to information about the daughters' reproductive health. This is the first scientific report of a link between DDT and reproductive outcome in women exposed to the contaminant in the womb. Curiously, higher DDE levels were associated with a modest reduction in the effect. Posted 27 June 2003. More... Strong link established between pesticide exposure and reduced sperm quality in mid-West men. Research in the US mid-West has discovered that men with elevated exposures to alachlor, diazinon and atrazine are dramatically more likely to have reduced sperm quality. The study is the first to show such a link for common, current-use pesticides, and its findings are particularly troubling because the most likely route of exposure is through drinking water. The three pesticides implicated by the research are widespread contaminants in mid-West water systems. More... Study questions low level effects of methyl mercury. A study of children in the Seychelles Islands indicates a mother's consumption of ocean fish with low levels of methyl mercury does not harm fetal brain development. This work conflicts with earlier research on the psychomotor impacts of methyl mercury. 21 May 2003. More... Pesticide applicators at greater risk to prostate cancer. A large study of pesticide applicators in Iowa and North Carolina reveals a small but significant increase in prostate cancer risk compared to the general population. The results are consistent with previous findings of elevated prostate cancer risk in farmers. Use of methyl bromide and of chlorinated pesticides showed the clearest association with higher prostate cancer risk. 20 May 2003. More... 26 December 2002. Research in Sweden reveals a link between organochlorine levels in a mother's blood and the risk that her son will develop testicular cancer, decades after birth. The son's own contamination levels, measured at the time of cancer diagnosis, provide few insights into risk. These data are consistent with the proposal that testicular cancer in adulthood results from errors in fetal testicular development caused by hormone disruption. More... 12 December 2002. A study of men living in the Boston area suggests that adult exposure to phthalates can damage the DNA of human sperm. The damage was detected at phthalate exposure levels common within the American public. It is unknown whether the amount of DNA damage would lead to infertility or genetic problems in offspring. More... 11 November 2002. In the most sophisticated study of geographic variation in US sperm count yet conducted, scientists from four different geographic regions across America report they find important differences in sperm density and motility. Men in Missouri have the lowest sperm count compared to New York, Minneapolis and Los Angeles. The cause of these differences are not yet known. The scientists conducting the study hypothesize it may be related to the intensity of pesticide use in industrial agriculture in Missouri compared to the other, more urban areas. More... September 2002. Dutch scientists report that boys exposed prenatally to higher levels of PCBs and dioxin are more likely to show demasculinized play behaviors. Girls and boys exposed to modestly elevated dioxin levels demonstrate more feminized play behaviors. The scientists suggest that that these alterations in play result from endocrine disruption of the development of sex-specific behaviors. More... August 2002. A study by the Northern California Childhood Leukemia Study (NCCLS) adds new strength to suspected links between pesticides and childhood leukemia. Pesticide use in the home had its largest effect on childhood leukemia risk during pregnancy. Pesticide application by professionals did not appear to help. In fact, professional pest applications were associated with a more-than-doubling of risk. More frequent applications led to greater risk, also. Bottom line: avoid home pesticide use if you want to minimize the risk of childhood leukemia in your family. More... August 2002. An ambitious, federally funded study of breast cancer on Long Island found few apparent links between breast cancer risk and a suite of organochlorines, including DDT and PCBs. Limitations in the study design, however, limit the strength of any conclusions. More... July 2002. Results from Taiwan provide strong support for earlier studies suggesting that exposure prior to adulthood to dioxin-like compounds will decrease the likelihood of fathering male offspring. This effect of contamination may be contributing to declines in the proportion of boys born in a number of industrialized countries. More... May 2002. An international team of epidemiologists published a study of women exposed to dioxin during the 1976 chemical plant explosion in Seveso, Italy. Their results indicate that the risk of breast cancer is increased by exposure to dioxin. Their research is especially valuable because the assessment of chemical exposure is based on blood samples gathered shortly after the explosion, and because now over two decades have passed since exposure, allowing for impacts with long latencies to be manifest. This is very unusual in studies of breast cancer and adds to the importance of their findings. More... July 2001. A study in The Lancet strongly suggests that exposure in the womb to DDE may cause premature birth and small size at birth (controlling for gestational age). The study examined birth records and contamination data gathered between 1959 and 1966 in urban areas in the United States. Compared to other risk factors associated with premature birth and small size at birth, the apparent impact of DDE was quite large. While DDE levels have now dropped below these levels in the US , this study raises serious questions for countries where DDT continues to be used for vector control because of the link between premature birth and infant mortality. More... July 2001. A study published in 2000 reveals a strong statistical association between undescended testes in young boys and levels of two organochlorine contaminants in their fat tissue, HCE and HCB. More on the study... The results are consistent with emerging molecular data on causes of cryptorchidism. Estrogenic substances interfere with expression of genes crucial to normal testicular descent. More on the causes... January 2001. Based on the largest number of women with documented exposure to diethylstilbestrol in the womb, a study published in Obstetrics & Gynecology (October 2000) confirms that women exposed to DES during development in the womb suffer, throughout their reproductive life, from worse pregnancy outcomes than unexposed counterparts. They are less likely to have had full-term live births, as well as more likely to have premature births, spontaneous pregnancy losses and ectopic pregnancies. More... January 2001. Scientists report a strong association between exposure to commercially applied agricultural pesticides during a crucial period in fetal development and the likelihood of fetal death due to congenital defects. The closer mothers lived to the location of commercial pesticide applications, the more likely was fetal death. More... Paulozzi,
LJ, JD Erickson and RJ Jackson. 1997. Hypospadias
trends in two US surveillance systems. Pediatrics 100:831-834 Hypospadias is a birth defect in the penis when the opening is displaced from the tip of the shaft; in its most extreme form it occurs at the base. Cryptorchidism is a condition in which one or both testicles do not descend into the scrotum. European research has shown that both are part of a syndrome of disorders of the male reproductive tract associated with higher rates of testicular cancer (in adulthood), lower sperm counts and lower fertility. These papers by Paulozzi and Paulozzi et al. examine US regional and national trends in hypospadias, and international trends in both hypospadias and cryptorchidism. Other reviews are also available (e.g., Toppari et al. 1996). The US data indicate a doubling in hypospadias rates since 1970. The international data reveal a more complicated picture, which (if endocrine disruption is a causal factor) should not be surprising because of the heterogeneity of exposures and heterogeneity of genetic susceptibility to contamination. For non-US trends , Paulozzi concludes "there is some evidence for an increase in hypospadias rates concentrated in more affluent nations. That increase may have ended in the mid-1980s. ... Assuming these upward trends are real and assuming exogenous agents are responsible, the relevant exposures may be more common in highly industrialized countries. Those exposures (or their body burdens) that may have stabilized since 1985 might also be the most logical ones to pursue among all potential environmental exposures." |
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Rothman, N., K. P. Cantor, A Blair, D Bush, JW Brock, K Helzlsouer, SH Zahm, LL Needham, GR Pearson, RN Hoover, GW Comstock, PT Strickland. 1997. A nested case-control study of non-Hodgkin lymphoma and serum organochlorine residues. The Lancet 350 (July 26): 240-244. Rothman et al. found a powerful interaction between levels of PCB exposure, exposure to Epstein Barr virus, and the risk of non-Hodgkin's Lymphoma (NHL), a hormonally-based cancer that has been increasing steadily within the US. Without elevated exposures to PCB, exposure to the virus did not appear to raise the risk of NHL. Without elevated exposure to the virus, PCB exposure had only a modest effect. But elevated levels of both risk factors dramatically increased the risk to NHL, by over 20-fold. This paper is especially important because it focuses attention on potential synergies between infectious disease agents and contamination. Its findings suggest that to understand the consequences of exposure to infectious agents, it may be essential to understand the contamination history of the people involved. More on their research findings... Other studies indicating immune system impacts. |
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Garry, VF, D Schreinemachers, ME Harkins and J Griffith. 1996. Pesticide appliers, biocides and birth defects in rural Minnesota. Environmental Health Perspectives. 104(4): 394-399. Garry et al. found dramatic concordance between birth defects in Minnesota and the geography and timing of pesticide use, including several potent endocrine disrupters. According to their analysis, higher rates of birth defects occur not only in the children of farmers, who are directly exposed to the chemicals at work, but also in the children of families living in predominantly agricultural regions in the state where fungicides and chlorophenoxy herbicides are most heavily used. Children conceived in the spring, when these herbicides are routinely applied, are at particular risk of birth defects, the study found. In another intriguing finding, the researchers noted that birth defects occur at a much higher rate in the male offspring of farmers and than in the normal population. Garry et al. report that that birth anomalies increase by 1.5 per hundred births comparing the lowest risk group with the highest risk group. That increase is four orders of magnitude greater than the 1 in a million standard commonly applied in regulatory toxicology, and the low risk group was not a zero baseline, because it is impossible to find a control group where there has been zero exposure. |
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García-Rodríguez,1 R, M García-Martín, M Nogueras-Ocaña, J de Dios Luna-del-Castillo, M Espigares García, N Olea, P Lardelli-Claret. 1996. Exposure to Pesticides and Cryptorchidism: Geographical Evidence of a Possible Association. Environmental Health Perspectives 104(10):1090-1095. Along with other disorders of the male reproductive tract, data suggest that cryptorchidism (undescended testes) has increased in recent decades, at least in some regions of the world. Garcia-Rodriguez et al. carried out an epidemiological study of the frequency of cryptorchidism in boys aged 1-16 in relation to the geography of pesticide use in the province of Granada, Spain. Their findings "are compatible with a hypothetical association between exposure to hormone-disrupting chemicals and the induction of cryptorchidism." They caution, however, that methodological limitations "make it necessary to evaluate the results with caution." |
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Sherman, JD. 1995. Chlorpyrifos (Dursban)-associated birth defects: a proposed syndrome, report of four cases, and discussion of the toxicology. International Journal of Occupational Medicine and Toxicology 4(4):1-13. In an anecdotal but intriguing study, Sherman presents data on four cases involving an unusual pattern of birth defects affecting the eye, ear, palate, teeth, heart, feet, nipples, genitalia and brain. Genital defects include undescended testes, microphallus and fused labia. Each of the children was exposed in utero to a pesticide product containing chlorpyrifos. This compound is unusual in that it is an organophosphate, an organochlorine and also an organosulphate. Sherman includes a summary of relevant literature. The public policy debate about Dursban heated up dramatically in spring 2000. |