Endocrine disrupting chemicals (EDCs) are found in a variety of products, such as pesticides, wood preservatives, paints and plastics as well as occurring naturally, in some plants. These chemicals interfere with the working of the hormone system in mammals, birds, amphibians and fish. Their potential health effects include reproductive disorders, cancer and impaired development. In January 1998, the Environment Agency1 launched a consultation exercise urging companies to take precautionary measures to protect the environment from endocrine disrupting chemicals. In 1999, the Federal Environment Agency2 in Germany published a list of pesticides they considered to be confirmed or potential endocrine disrupters, some of these are described below.
The endocrine system is vital to the functioning of plants and animals,
controlling growth, maintenance and reproduction. It comprises a complex
system of chemical messages (hormones) that trigger particular organs
to produce a response, e.g. produce sperm, cause cells to multiply and
cause cells to differentiate and develop new functions. This chemical
message system is based on very low concentrations of hormones. Thus,
powerful messages can be sent around the body of plants and animals
with tiny amounts of hormones. In vertebrates the hormones are carried
in the blood supply. The endocrine system is particularly active during
the development of the foetus and reproductive systems later in life.
Endocrine disrupting chemicals (EDCs) fool target cells into behaving
differently. They act in several ways, including:
Endocrine disruption is therefore extremely complex and studies of
how it occurs are hampered by the lack of a full understanding of how
natural hormones are produced and work. However, there is a growing
body of evidence that a large number of chemicals are involved and that
the effects could be conserable on both humans and their environment.
In humans, several health problems (listed below) which may be linked
to EDCs have been recorded3.
In wildlife, the following are examples of effects which have been
linked to EDCs:
Further details of these can be found in the Environment Agency report8.
Endocrine disruption in wildlife has already been shown to threaten
populations of species.
The research necessary to confirm which chemicals can be classed as
EDCs and how they interfere with hormones is still being carried out.
However, the Environment Agency has stated that there should be action
to reduce further environmental exposure whilst this research is progressing.
The list of chemicals proven to be EDCs is likely to grow as more research
is carried out and so is the list of products affected. The evidence
against the pesticides vinclozolin and carbendazim is very strong. Residues
of both of these have been regularly found on fruit and vegetables since
1995 (see below).
EDCs in the environment come from a wide range of sources, including
some natural ones. Pesticide residues on food are just one of the ways
in which humans are exposed to these chemicals and the cumulative effects
are unknown. Some of the chemicals under scrutiny, and their sources,
are listed below.
Many different chemicals have been found to be potential EDCs including
the following:
Chemicals used in industrial detergents, paints/varnishes, plastics
and pesticides such as Alkylphenols and alkyl phenol ethoxylates.
For example, Bisphenol A (BPA) is used in plastic manufacture (including
plastic bottles) as a stabiliser, and in linings of steel tinplate food
cans and water pipes. Phthalates are plasticisers (making plastic more
flexible) used in PVC and in a range of products including toys, inks,
paints and adhesives.
These are naturally occuring in plant materials, including soya. Humans
are usually able to break these down rapidly but there are concerns
about the use of soya based infant foods which are not a natural part
of our diet9.
Several widely used pesticides are known or potential EDCs including atrazine, benomyl, carbendazim, carbufuran, chlorpyrifos, dimethoate, DDT, lindane, vinclozolin and synthetic pyrethroids such as deltamethrin. Further details about three of these are given below.
The thresholds for pesticide residues are agreed internationally by
the Codex Alimentarius Commission (CAC). CAC is a joint body of the
Food and Agriculture Organisation of the UN and the World Health Organisation
(WHO). The CAC standards are set to protect consumer health and facilitate
trade and are used by the World Trade Organisation to regulate trade.
For pesticides CAC has agreed Maximum Residue Levels (MRL) for many
but not all foods. MRLs are based on theAcceptable Daily Intake (ADI)
agreed by the WHO with a considerable safety margin. However, safety
assessments by the WHO do not take into account possible endocrine disrupting
properties of pesticides. Many products currently licensed have not
been screened as EDCs. Many MRLs may well be too high to exclude hormone
disruption as a possible effect of being exposed to residues in food.
The pesticide approval process (The Control of Pesticides Regulations
1986, the Plant Protection Products Regulations 1995 and The Food and
Environment Protection Act 1985) may require endocrine disruption to
be screened before new products enter the market in the future. Older
pesticides are currently being reviewed at present but this does not
include a review of endocrine disruption. The Pesticide Safety Directorate(PSD)
monitors the standard tests for reproductive function and carcinogenicity
which may indicate endocrine disruption. However, pesticide formulations
with possible EDCs as active ingredients are still being given PSD and
Health & Safety Executive (HSE) approval. There is also a major
review of pesticide safety data taking place in preparation for the
harmonization of pesticide regulations and approvals within the EU.
Pesticides which have been shown to affect hormone systems are frequently
used in UK agriculture. Residues of these products are often found by
routine sampling carried out by MAFF. These surveys have also found
endocrine disrupting pesticides in imported products.
Usage
This is registered as a fungicide for use on oilseed rape, apples, peas
and beans. It is not widely used onapples or oilseed, but was used on
a quarter of peas and beans in 199510.
Residues
Since 1995, it has been detected on imported celery, grapes, kiwi fruit,
lettuce, pears, sweet peppers and tomatoes, as well as on UK lettuce,
strawberries and pears. In the 1998 surveys by MAFF and the UK Industry
(published in 1999) 11,
no residues were found on UK lettuces (it is not approved for such use
in the UK) although illegal use of other fungicides was found. However
Vinclozolin was detected in some samples of tomatoes (also a non- approved
use) and kiwi fruit.
Toxicity
Vinclozolin is a proven endocrine disrupter, causing anti-androgenic
('anti-maleness') effects. It does this by binding to the natural male
hormone receptors. Studies on rats found that exposure of male rats
in the womb and shortly after birth to low doses of vinclozolin lead
to a range of sex organ changes12.
Young male rats exposed to vinclozolin showed delayed puberty13.
Usage
This is the most commonly used fungicide in the UK.
It is registered for use as a fungicide on Brussels sprouts, blackcurrants,
gooseberries, beans, lettuce, black berries, loganberries, raspberries,
tomatoes, oilseed rape, cucumbers, pepper, strawberries, celery, onions,
cherries, plums, apples, barley, wheat, winter rye, mushrooms, stored
fruit, cabbages and potatoes.
Residues
Since 1995 it has been detected on UK apples, UK and imported celery,
grapes, marmalade, UK and imported pears, apricots, bananas, imported
cucumbers, mixed dried fruit, retail and 'pick your own' gooseberries,
peaches, imported and 'pick your own' strawberries, imported tomato
products,clementines and UK green beans. In the 1998 MAFF & industry
surveys, residues were detected in several samples of UK and imported
apples, as well as in some samples of tomatoes, grapes, lemons, lettuce
and mango.
Carbendazim has also been detected in processed products such as fruit
based infant food, canned fruit, fruit squash and fruit
juice.
Toxicity
Carbendazim disrupts the production of sperm and damages testicular
development in adult rats. In addition, carbendazim is a teratogen _
damaging development of mammals in the womb. Rats developing in the
womb and exposed to Carbendazim, have been found to lead to deformities
such as lack of eyes and hydrocephalus (“water on the brain”)14.
Usage
Lindane is still approved for use on food and fodder crops in the UK,
including apples and in grain stores. Recent pesticide usage surveys
show that over 41 tones of lindane have been applied to farm crops over
one year15.
Following a recent safety review, MAFF announced that its approval as
a seed dressing was withdrawn because of risk of exposure to workers.
Residues
Residues of lindane commonly occur in chocolate. In the 1998 survey
by the UK food industry, all samples of chocolate and cocoa butter contained
lindane. Although these were below the MRL, this is no guarantee of
safety (see above). The likely source of this lindane is its use on
the cocoa crop. In 1998 lindane residues were also found in milk, infant
formula milk and cheese.
Toxicity
The Austrian Ministry of Agriculture16
carried out a review of the toxicity of lindane for the EC and pointed
to serious gaps in the data on health effects.The review concludes that
lindane should be “suspended from the market”. One of its
main concerns is the possible link between lindane and cancer.
Exposure to endocrine disrupting pesticide residues in food poses a
significant health risk to humans. The long-term consequences of such
exposure are difficult to assess but the current state of scientific
information suggests that a highly precautionary approach is needed
to avoid serious health problems in the future.
Written by Pete Riley, Sandra Bell and Michael Warhurst
October 1999.
The Real Food Campaign
Friends of the Earth
26-28, Underwood Street
LONDON
N1 7JQ
Tel 020 7490 1555
Fax 020 7490 0881
Email - info@foe.co.uk
Website - www.foe.co.uk
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1.Environment Agency, 1998, Endocrine - disrupting substances in the
Environment: what should be done? Consultation paper
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2.ENDS, 1999, Industry glimpses new challenges as endocrine science
advances. ENDS Report 290: 26-30
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3.Friends of the Earth, Poisoning our children: The dangers of exposure
to untested and toxic chemicals. Briefing
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4.Swann, S.H., Elkin, E. P. and Fenster, L., 1997, Have sperm densities
declined? A reanalysis of global trend data. Environmental Health Perspectives
105. p1228-1232
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5.Cancer Research Campaign Data, January 1998
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6.Cancer Research Campaign Data, January 1998
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7.Institute for Environment and Health, 1995, Environmental Oestrogens:
consequences to human health and wildlife.
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8.Environment Agency, 1998, Endocrine - disrupting substances in the
Environment: what should be done? Consultation paper
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9.Friends of the Earth, Poisoning our children: The dangers of exposure
to untested and toxic chemicals. Briefing
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10.Ministry o f Agriculture, Fisheries and Food, 1995, Pesticides Usage
Survey Report 134: Outdoor Vegetable Crops in Great Britain 1995.
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11.Ministry of Agriculture, Fisheries and Food, Pesticides Safety Directorate,
Health and Safety Executive. 1999, Annual report of the Working Party
on Pesticide Residues 1998
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12.Gray, L. E., Ostby, J., Monosson, E. and Kelce, W.R., 1999, Environmental
antiandrogens: low doses of the fungicide vinclozolin alter sexual differentiation
of the male rat. Toxicology and Industrial Health 15: 48-64
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13.Monosson, E., W.R., Lambright, C., Ostby, J. and GRay, L.E.J., 1999,
Peripubertal exposure to the antiandrogenic fungicide, vinclozolin,
delays puberty, inhibits the development of androgen-dependent tissues,
and alters androgen receptor functions in the male rat. Toxicology and
Inustrial Health 15: 65-79
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14.Mantovani, A., Maranghi, F., Ricciardi, C., Macrì, C., Stazi,
A. V., Attias, L. and Zapponi, G. A., 1998, Developmental toxicity of
carbendazim:: Comparison of no-observed-adverse-effect level and benchmark
dose approach. Food and Chemical Toxicology 36: 37-45
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15.Calculated using data from Ministry of Agriculture, Fisheries and
Food, Pesticide Usage Surveys (1994/97)
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16.Federal Ministry of Agriculture and Forestry, 1998, Lindane Vol 1
Report & Proposed Decision: Monograph prepared in the context of
inclusion of the following active substances in Annex 1 of Council Directive
91/414/EEC
Contact details:
Friends of the Earth
26-28 Underwood St.
LONDON
N1 7JQ
Tel: 020 7490 1555
Fax: 020 7490 0881
Email: info@foe.co.uk
Website: www.foe.co.uk
October 1999
Pete Riley, Sandra Bell and Michael
Warhurst
Last modified: June 2001
