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...
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...
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...
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...
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...
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...
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...
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...
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
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.
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...
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...
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.
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...
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.
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...
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...
LJ, JD Erickson and RJ Jackson. 1997. Hypospadias
trends in two US surveillance systems. Pediatrics 100:831-834
Paulozzi, LJ. 1999. International trends in rates of hypospadias
and cryptorchidism. Environmental Health Perspectives 107:297-302
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.
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).
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.
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."