Hormones in the environment: how the facts were covered up
By Paul Mitchell
20 September 2000
Every male fish in some European rivers shows pronounced female
characteristics, according to Professor Alan Pickering of the Natural
Environment Research Council. Speaking to the British Association's
Festival of Science in London earlier this month, Pickering said, "We
are finding this problem right across northern Europe, it is clearly
widespread."
Pickering said that "It seems to relate to a mixture of chemicals
both industrial and also some of the natural excretory products from the
human body." These substances, known as endocrine disrupting chemicals
(EDCs) or “gender-benders”, are found in some agrochemicals, paints,
oils, toiletry products and detergents. They mimic the hormones produced
by the female ovaries and the male testes in animals, which regulate
growth and reproduction.
The evidence that they affect human health is conflicting and
controversial. According to a report by the Royal Society in June 2000,
“Humans are exposed daily to environmental chemicals which have
potential endocrine disrupting activity, raising concerns, provided that
the level of exposure is sufficient, that such chemicals might be linked
with phenomena such as declining sperm count in the adult male,
testicular cancer, breast cancer, age at puberty, etc.” The incidence of
testicular cancer, for example, has increased three-fold in the last
thirty years in Britain, becoming the commonest cancer in young men.
However, the situation is complex, also involving genetic and dietary
factors. Breast cancer in China and Japan is much lower than in Western
countries. Scientists think this could be linked to a high-fibre, low
fat diet, and yet there is high consumption of soya in these countries,
which produces weak EDCs.
Because humans produce hormones in their bodies naturally, the
effects of EDCs are difficult to unravel. But it is thought possible
that the foetus, which is naturally protected from the high levels of
hormones in its pregnant mother, could still be affected.
Chemicals that are now known to be EDCs were first manufactured in
the 1930s. In 1938 researchers showed that medicines containing them
could cause reproductive changes. In the 1950s and 60s, a synthetic
female hormone, diethylstilbesrol, given to prevent miscarriages
increased vaginal abnormalities in mothers and reduced fertility in some
of the six million babies that were exposed to it.
Evidence of similar effects in the environment was developing.
Pesticides such as DDT caused reproductive problems in animals and
paints used on ships to prevent the growth of barnacles led to shellfish
sterility.
In England, the government-run Water Research Centre published a
report called Steroids as Water Pollutants in 1976. (Steroids
include the female hormone oestrogen and its male counterpart
testosterone, as well as hormones produced by the adrenal gland.)
At about the same time abnormal fish were noticed in rivers in
southern England downstream of sewage works. Scientists first thought
pharmaceutical factory wastes discharging into the sewers were the
cause. Research into the abnormalities was carried out in 1981 by
Liverpool University, commissioned by the then state-owned water
authorities. It was never published because they claimed the research
was flawed.
The Ministry of Agriculture carried out a further investigation in
1988 that showed “all sewage treatment works effluents were oestrogenic
to fish and whatever chemical, or mixture of chemicals was causing the
effects, it was ubiquitous”. It was suggested that natural and synthetic
oestrogens were the cause. The Conservative government kept these
potentially explosive discoveries confidential—they were in the middle
of privatising the water industry— until 1992. Even then the research
was only published in a magazine produced by the Foundation for Water
Research that had a restricted circulation within government departments
and the water industry.
A further one-off study was commissioned by the government to look at
river water used in the public water supply. It concluded there was
“insufficient evidence to justify general regulatory action, other than
further research”. It appears that the EDCs in sewage break down in the
river or are destroyed in the water treatment works.
This research was also intended to be confidential, but in 1993
specialist magazines, then newspapers and the BBC's Countryfile
program had picked up the Foundation for Water Research report. The BBC
program Horizon later that year brought the issue to wider
public attention. It accused the water companies and government of a
cover-up. It quoted a water company spokesman who said, “There is no
need and no requirement in the United Kingdom Water Quality Regulations
to look for these substances. Nor are sufficiently sensitive techniques
available. Hence routine monitoring has not been carried out”.
Although the regulations say the companies should monitor for a few
dozen specific substances, they also say the companies should monitor
for any other substance that could be injurious to public health. It is
likely the companies have monitored for hormones in the public water
supply, despite the difficulties of analysis. The results have never
been made public, even though the companies say the treatment process
destroys hormones and the water is safe. (One might ask, if the methods
used to analyse hormones were suspect, how could the companies say the
water was safe?)
This year the Labour government has updated the Regulations in line
with revised European legislation, but EDCs are not mentioned
specifically. How much of this was due to lobbying by the powerful water
industry group EUREAU is uncertain.
In the meantime, Britain's water companies have other problems. They
have carried out a large program of water pipe renewal. To cut costs
existing pipes have been lined inside with plastic rather than being dug
up and replaced. This involved the use of epoxy resins containing
bisphenol-A, another EDC, to harden the plastic. In 1995, Welsh Water
was prosecuted for not checking the resins had set before using the
renovated pipe work for drinking water.
Despite this evidence and an Environment Agency report in 1997 that
enzymes in sewage re-activated hormones normally excreted by humans in
an inactive form, the government said the following year that it had
“made no estimates of cost of removal since the impacts are unclear”.
Recent scientific evidence confirms the suggestion made in 1988 that
two natural human hormones and one synthetic contraceptive hormone are
the likely EDCs in sewage works' discharges. On the River Aire in
Yorkshire it is chemical rather than human substances that are
responsible—an industrial detergent used for cleaning wool in the
remaining mills along this waterway.
It is clear that the British government and the water companies have
worked together to minimise the impact of the revelations. The House of
Lords also criticised water companies for doing the bare minimum of
research into water safety compared to the huge profits they have made
since privatisation. The situation has been further complicated by the
confidentiality surrounding the precise chemical formulae of many
industrial products.
Vital time has been lost in the scientific resolution of this complex
environmental problem. The Royal Society recommended in its June 2000
report that the “effects of endocrine chemicals released into the
environment” should be further investigated and that “regulations cannot
be ‘put on hold' until all the evidence has been collected”. Twenty five
years after the first abnormal fish were discovered in Britain's rivers,
the report notes that, “Few, if any, studies have attempted to look for
such evidence” affecting human health and there has been “no guidelines
on testing pharmaceuticals for environmental impact, despite the fact
that these chemicals are designed to be extremely potent and to degrade
slowly.”
https://www.wsws.org/en/articles/2000/09/oest-s20.html
|