Report from the Sub-comittee on the environment and health

Effects on reproduction
Developmental toxicity
1983). O<strong>the</strong>r pesticides, such as ethylene dibromide, kepon and carbaryl
have been associated with reproductive effects in males (Baker,
Wilkinson 1990). In some studies an association has been found between
miscarriage and foetal death and occupational exposure to pesticides
(Pastore et al. 1997; Goulet, Thériault 1991), whereas o<strong>the</strong>r studies have
been unable to demonstrate such a relationship (Restrepo et al. 1990;
Willis et al. 1993; Kristensen et al. 1997a).
In a review article <strong>from</strong> 1995 it is concluded that <strong>the</strong>re is no clear
epidemiological evidence of a relationship between exposure to
pesticides and increased reproductive risk (Nurminen 1995). A large
Norwegian study of congenital deformities in children born of parents
that were registered as farmers found an association between pesticides
and deformed sex organs (Kristensen et al. 1997b). A large review article
was published recently on studies concerning potential associations
between foetal deaths, miscarriages and stillbirths and specific pesticides,
toge<strong>the</strong>r with parents’ employment in occupations with potential
exposure (Arbuckle, Sever 1998). Data indicated an increased risk of
foetal death associated with pesticides in general and <strong>the</strong> mo<strong>the</strong>r’s
employment in agriculture. However, it was concluded in <strong>the</strong> review that
<strong>the</strong> studies carried out to date do not answer <strong>the</strong> question concerning <strong>the</strong>
toxic effect of individual pesticides on human reproduction.
A study of greenhouse workers showed significantly reduced plasmacholinesterase
activity compared with an unexposed control group
(Lander et al. 1995). In a study of semen quality and chromosomal
damage in greenhouse workers exposed to pesticides, no link was found
between individual factors, including exposure to pesticides. That
applied both to specific linkage with measured exposures to pesticides
and broad linkage with <strong>the</strong> market garden’s use of pesticides (Abell et al.
1997). The most important observation was that both chromosomal
damage and sperm quality were related to <strong>the</strong> current pesticide exposure
and that spraying was less important than exposure on re-entry. The
study revealed no differences between <strong>the</strong> greenhouse workers’ sperm
quality and <strong>the</strong> sperm quality of organic cultivators. In addition, <strong>the</strong>
greenhouse workers had a generally higher sperm quality than <strong>the</strong>
general population. On <strong>the</strong> o<strong>the</strong>r hand, it was observed that <strong>the</strong> longer <strong>the</strong>
persons studied had worked in horticulture, <strong>the</strong> poorer <strong>the</strong> sperm quality.
However, this was not unambiguously correlated with pesticide
exposure, nor was a correlation found between <strong>the</strong> pesticide consumption
of <strong>the</strong> market garden in question and sperm quality, although <strong>the</strong> workers
with a low exposure had a better sperm quality than those with a high
exposure. The results of <strong>the</strong> study indicate a need for increased action to
reduce exposure of greenhouse workers when handling sprayed plants.
Several studies have shown developmental effects as a consequence of
parents’ occupational exposure to pesticides. In <strong>the</strong> above-mentioned
Norwegian study of congenital deformities among newborn children of
parents registered as farmers, a moderately increased risk of spina bifida
and hydrocephalus was found, compared with children born of parents in
o<strong>the</strong>r occupations in rural communities. The risk was greatest in <strong>the</strong> case
of exposure to pesticides in orchards and greenhouses (Kristensen et al.
1997b). Exposure to pesticides, particularly in <strong>the</strong> case of arable farmers,
was also associated with limb defects. A Dutch study <strong>from</strong> 1996 showed
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