Download - Pesticides: Pregnancy outcome and fertility Markku Sallmén Finnish Institute of Occupational Health
Pesticides: Pregnancy outcome and fertility
Markku Sallmén
Finnish Institute of Occupational Health
Pesticides
The most extensively used group of toxic chemicals
ca. 600 different active ingradients about 50,000 various formulations simultaneous exposure to different
chemicals typical pesticide formulations may contain
solvents
Pesticides
Comparison between studies difficult Different pesticides are used for different
purposes and in different areas Exposure levels vary considerably; the
highest exposures occur in developing countries in poorly controlled circumstances
What is the affected gender?
DBCP
The nematocide DBCP (dibromochloro-propane) is the most impressive occupational testicular toxin in men
Toxic to spermatogonia, thus causing azoospermia and oligospermia
only some affected workers had recovered from azoospermia to normal sperm count 7-11 years after exposure
Pesticides shown adverse effects on spermatogenesis
DBCP 2,4-D (2,4-dichlorophenoxy acetic acid) ethylene dibromide chlordecone carbaryl
Agent Orange
A mixture of 2,4-D and 2,4,5-T (2,4,5-trichlorophenoxy acetic acid
Association between paternal exposure and anencephaly and orofacial clefts
Lowered sperm quality 10-20 years after military service among American Vietnam veterans
Pesticides and male fecundability
Study Association de Cock et al 1994 + Larsen et al 1998 - Thonneau et al 1999 - Curtis et al 1999 - Petrelli et al 2001 + Sallmén et al 2003 (+)+ = reduced fecundability, (+) suggestive association
Pesticides and couples undergoing IVF treatment (Tielemans et al)
Reduced fertilization capacity
Improved implantation rate
Summary effect ?
Male pesticide exposure and spontaneous abortion
Savitz et al 1994 reviewed 14 studies
elevated RR in >1 study: YES RR > 1.5 YES Evidence from high
quality studies: NO
Male pesticide exposure and spontaneous abortion
Study Association (OR) Arbuckle et al 1999
farm couples, phenoxy herbicides
<20 weeks of gestation 1.1 0.6-1.9
<12 weeks of gestation 2.5 1.0-6.4
husband not using protective 5.0 0.7-36.2
equipment
Petrelli et al 2000 3.8 1.2-12.0 Crisostomo et al 2002 6.17 1.37-27.86
Male pesticide exposure and spontaneous abortion
Arbuckle et al 2001Ontario farm population
timing of exposure:
preconceptional early (12 weeks) abortions
postconceptional late (12-19 weeks) abortions
Male pesticide exposure and congenital malformations
García 1998, a review on occupational exposure and congenital malformations17 studies 4 studies showed an association
Conclusion: Inadequate evidence for either establishing a relationship between pesticides exposure in humans and birth defects or for rejecting it.
Male pesticide exposure and congenital malformations
Pesticide applicators in the Red River Valley of Minnesota (Garry et al, 1996, 2002)1996 a register-based study
- excess in birth defects
- seasonal pattern
2002 a cross-sectional interview study- rate of birth defects 7.6% (spring) vs. 3.7% other season
- herbicides: risk of birth defects
- fungisides: determination of sex of the children
Pesticides and female fertility
Study Association
Fuortes et al 1997 + Curtis et al 1999 - Abell et al 2000 + Greenlee et al 2003 +
+ = reduced fertility
DDT/DDE and female fertility:a two-generation study (Cohn et al 2003)
Maternal serum Fecundability of
concentration the daughter
increasing DDT reduced fec.
increasing DDE increased fec.
Female pesticide exposure and pregnancy outcome
Nurminen 1995, a review
Definition of exposure: ecological 5 studies place of residence 5 studies agricultural occupation 10 studies exposure at work 9 studies Conclusion: the epidemiologic evidence is
inconclusive as regards the risk of adverse pregnancy outcome
Female pesticide exposure and spontaneous abortion
Study
Association
Bell et al 2001
pesticides showed no strong association with fetal death
Female pesticide exposure and congenital malformations
Study Association (OR)
Medina-Carillo et al 2002 6.33 2.95-13.7
occupational exposure
Bell et al 2001 risk of malformation
increased within the
same square mile than the application
Parental pesticide exposure and congenital malformations
Kristensen et al 1997; a study among Norwegian farmers
Exposure to pesticides associated with:
spina bifida
hydrocephaly
limb reduction
cryptorchidism
hypospadias
Female DDT/DDE exposure and preterm birth and birth weight
StudyAssociation (OR)Longnecker et al 2001 concentration of DDE maternal serum DDE related to preterm birth in a dose- response manner
Torres-Arreola et al 2003 a weak association maternal serum DDE with preterm birth
Gladen at al 2003 no association with maternal milk DDE birth weight
Parental pesticide exposure and childhood cancer
There seems to be an association between father's work in agriculture and increased risk of brain tumors in their children
Kristensen et al (1996): use of pesticides was associated with cancer at early age
birth-month examination suggested paternal-mediated mechanism of pesticides
Pesticides conclusion
Several adverse outcomes in numerous studies
some studies negative the evidence suggest, that exposure is
associated with reproductive hazards => exposure should be restricted Problem: few harmful agents identified!