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Father’s Day Report Notes Greater Environmental Risks To Boys

Tuesday, July 10, 2007
Posted in Environment Health | Tagged Environment, Health

1. Father’s Day Report Notes Greater Environmental Risks To Boys
� “All children are at risk from exposure to environmental hazards,
� but boys appear to be at greater risk,” said Dr. Lynn Marshall, with
� the Ontario College of Family Physicians. “For health outcomes such as
� asthma, cancer, learning and behavioural problems and birth defects,
� the boys are faring worse than the girls,” noted Loren Vanderlinden,
� with Toronto Public Health.

2. A Flame Retardant Is Linked To a Common Birth Defect in Boys
� A new study links the common flame retardant, PBDE, to a common
� birth defect in boys.

3. The Mystery of the Missing Boys;
� The sex ratio among newborns has shifted and boys are no longer
� being born at the historical rate, compared to girls. Although
� researchers do not know why boys are taking a hit, they suspect
� contributing causes could include widespread exposure to hormone-
� mimicking pollutants by women during pregnancy and by men before they
� help conceive children.

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1. FATHER’S DAY REPORT NOTES GREATER ENVIRONMENTAL RISKS TO BOYS

Report urges precaution and increased awareness

Ottawa and Toronto: In a report released for Father’s Day, the
Canadian Partnership for Children’s Health and Environment urges
greater awareness among parents, especially fathers, about
environmental risks to boys. (Full report available here and report
summary available here.)

“All children are at risk from exposure to environmental hazards, but
boys appear to be at greater risk,” said Dr. Lynn Marshall, with the
Ontario College of Family Physicians.

The report summarizes the evidence about environmental risks to boys.
“For health outcomes such as asthma, cancer, learning and behavioural
problems and birth defects, the boys are faring worse than the girls,”
noted Loren Vanderlinden, with Toronto Public Health.

We know that the time of greatest vulnerability for children is in the
womb. It appears that boys are even more vulnerable than girls during
these critical developmental stages. Brain development in boys is of
particular concern. “Four times more boys than girls are affected by
autism and ADHD. Boys are also at increased risk for learning
disabilities, Tourette’s syndrome, cerebral palsy and dyslexia,” noted
Kathleen Cooper, with the Canadian Environmental Law Association.

The report summarizes what is known about environmental links to
health outcomes in children, noting the many areas of uncertainty.
Given the risks of lifelong impacts, it is better to be safe than
sorry. Like CPCHE’s other educational materials, the CPCHE Father’s
Day report seeks to raise public awareness. Fathers and all members of
society can take action to reduce or prevent environmental or
occupational exposures that can affect a fetus or child.

Kathleen Cooper, Senior Researcher, Canadian Environmental Law
Association 705-324-1608

Loren Vanderlinden, Supervisor, Environmental Health Assessment &
Policy, Environmental Protection Office, Toronto Public Health
416-338-8094

Dr. Lynn Marshall, co-chair, Environmental Health Committee, Ontario
College of Family Physicians 905-845-3462

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2. From: Environmental Science & Technology, Jun. 27, 2007

PBDES LINKED TO COMMON BIRTH DEFECT IN BOYS

By Kellyn S. Betts

Scientists have long suspected that children may be especially
vulnerable to the endocrine-disrupting effects of polybrominated
diphenyl ether (PBDE) flame retardants because the main route of
exposure to the chemicals is through consumer products in the home. A
new study by Katharina Maria Main of Rigshospitalet [2.8 Mbyte
PDF], part of the Copenhagen University Hospital, is the first to
link elevated PBDE levels with a human birth defect.

The study, published online May 31 in Environmental Health
Perspectives, associates cryptorchidism, a condition in which one or
both testicles fail to descend into the scrotum, with higher
concentrations of PBDEs in breast milk. The incidence of
cryptorchidism is increasing rapidly in some countries, which suggests
that environmental factors may be involved, according to the paper.
Main and her colleagues found that PBDE concentrations in the breast
milk of Danish and Finnish mothers of sons born with undescended
testicles were significantly higher than those in the breast milk of
mothers of sons with normal testicles.

Because testicular descent is strongly androgen-dependent, the
researchers say that the new findings are in line with a 2005 study
showing that PBDEs are antiandrogenic in mice. They also point out
that testicular cancer is the most severe symptom of testicular
dysgenesis syndrome, which also includes cryptorchidism. In 2006,
Swedish researchers linked early-onset testicular cancer with higher
levels of maternal PBDEs.

The new findings aren’t clear-cut, because researchers saw no
correlation between PBDE levels in the cord blood of infants in the
study and the incidence of cryptorchidism. Why this is the case is not
clear, the researchers write. They posit that the combined exposure to
multiple environmental factors may be responsible for the link they
observed between PBDE concentrations in mother’s milk and
cryptorchidism.

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3. From: Globe and Mail (Toronto, Canada) (pg. A4), Apr. 11, 2007

THE MYSTERY OF THE MISSING BOYS;

Chemical pollutants flagged in new study as possible factor in skewed
sex ratio

By Martin Mittelstaedt, Environment Reporter

Where are all the missing boys?

It is a question posed by a new study that has found the proportion
of boys born over the past three decades has unexpectedly dropped in
both the United States and Japan. In all, more than a quarter of a
million boys are missing, compared to what would have been expected
had the sex ratio existing in 1970 remained unchanged.

The study also says the world’s most skewed sex ratio is in Canada, in
a native community surrounded by petrochemical plants in Sarnia, Ont.,
where the number of boys born has plunged since the mid-1990s at a
rate never seen.

Although the researchers do not know why boys are taking a hit, they
suspect contributing causes could include widespread exposure to
hormone-mimicking pollutants by women during pregnancy and by men
before they help conceive children.

“We hypothesize that the decline in sex ratio in industrial countries
may be due, in part, to prenatal exposure to metalloestrogens and
other endocrine disrupting chemicals,” said the study, issued this
week in Environmental Health Perspectives, a peer reviewed journal of
the U.S. National Institute of Environmental Health Sciences.

These types of chemicals include some pesticides, dioxin and
methylmercury, a pollutant from coal-fired power plants and many
industrial sources commonly found in seafood.

The study also flagged a host of other possible factors, including
rising obesity rates, older parental age, growing stress levels, and
the increasing number of children being conceived using fertility
aides. Other research has shown some associations between these
factors and a drop in boy births.

The study was conducted by researchers in both the U.S. and Japan, and
led by Devra Lee Davis, a prominent epidemiologist and director of the
Center for Environmental Oncology at the University of Pittsburgh
Cancer Institute.

In an interview, Dr. Davis said that although the cause of the decline
isn’t known, it could be linked to the increasing number of other male
reproductive problems, such as falling sperm counts and rising
testicular cancer rates.

She said that males during fetal development may be more sensitive to
pollutants that mimic hormones, leading to increased fetal deaths and
reproductive problems later for the surviving males.

The situation in Sarnia, where nearly twice as many girls are being
born than boys on the Aamjiwnaang First Nation, is internationally
significant, according to the study. “To our knowledge, this is a more
significantly reduced sex ratio and greater rate of change than has
been reported previously anywhere,” it said.

The reserve is located in the heart of Sarnia’s chemical valley, and
the native community, along with researchers at the University of
Rochester and the Occupational Health Clinics for Ontario Workers, are
trying to find the cause of the unusual sex ratio.

Fewer boys than expected are being born in the non-aboriginal
community downwind of the petrochemical plants in the area, but not to
the same degree as on the reserve. The work force in Sarnia has not
been studied, something that would shed light on whether pollutants
are the cause.

Researchers in many countries have been reporting a drop in the ratio
of boys to girls being born over the past few decades.

It is considered normal in a large population for the number of baby
boys to slightly outnumber girls, by a proportion of about 105 males
to 100 females. It is widely thought that more boy births are a way
nature compensates for higher rates of male mortality.

But the ratio has not been static in industrialized countries, and
researchers suspect that increasing numbers of male fetuses are being
miscarried, a kind of sex-based culling in the womb.

In Japan, the sex ratio fluctuated with no trend from 1949 to 1970,
but then declined steadily to 1999, the end of the study period there.

The decline in the number of boys in Japan equals 37 out of every
10,000 births.

In the U.S., the sex ratio also declined from 1970 to 2002. The drop
in the number of boys equals 17 out of every 10,000 births.

The U.S. change was concentrated among whites. There was almost no
change among blacks.