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Solvents: pregnancy outcome and fertility. Marja-Liisa Lindbohm Finnish Institute of Occupational Health. Organic solvents. one of the most important occupational reproductive hazards: widely used in various fields of industry volatile liquids absorbed via inhalation and through the skin
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Solvents: pregnancy outcome and fertility Marja-Liisa Lindbohm Finnish Institute of Occupational Health
Organic solvents • one of the most important occupational reproductive hazards: • widely used in various fields of industry • volatile liquids • absorbed via inhalation and through the skin • most solvents traverse the placenta
Reproductive effects of solvents • teratogenic, embryotoxic and behavioral effects in animal tests on mammals • in several human studies exposure related to • adverse pregnancy outcome and reduced fertility • in some studies exposure related also to • menstrual disorders and reduced hormone levels • reduced semen quality • pregnancy-induced hypertension • neurobehavioral performance • childhood cancer
Industries / individual solvents related to reduced fertility or adverse pregnancy outcome • Dry cleaning / tetrachloroethylene • Shoe and leather industry / aliphatic hydrocarbons, toluene, hexane • Semiconductor industry / ethylene glycol ethers • Laboratory work / toluene, xylene, chloroform
Maternal exposure to tetrachloroethylene in dry cleaning and spontaneous abortion
Spontaneous abortion, subfertility and maternal exposure to ethylene glycol ethers in semiconductor industry (Correa et al. 1996)
Results of studies among women working in the shoe and leather industry • indications of an increased risk of perinatal death, stillbirth, and oral clefts in children of shoe and leather workers (likely exposed to solvents) • increased risk of spontaneous abortion and decreased fertility among shoe workers exposed to solvents (aliphatic hydrocarbons, toluene, hexane, acetone)
Cumulative percentage of pregnancies by maternal exposure to solvents (Sallmén et al 1995)
Maternal exposure to solvents and birth defects • McMartin et al. 1998: • meta-analysis of five studies (n=7036) • summary OR=1.64 (95% CI 1.16 - 2.30) • Solvent exposure linked with • central nervous system defects, oral clefts, gastroschisis, ventricular septal defects, urinary tract defects
Conclusions: Effects of solvent exposure on the reproductive health of women • High exposure to solvents increases the risk of spontaneous abortion and decreases fertility • The findings on birth defects less conclusive, but suggesting adverse effects • Particular solvents associated with adverse outcome: ethylene glycol ethers, tetrachloro-ethylene, toluene
Exposure to solvents and semen quality or hormone levels • 2-bromopropane: reduced sperm count • Ethylene glycol ethers: reduced sperm count • Styrene and acetone: sperm anomalies • Toluene: decrease of gonadotropin hormone levels • Trichloroethylene: hyperzoospermia • Solvents: low active sperm count and decreased implantation rate
Cumulative percentage of pregnancies by paternal exposure to solvents (Sallmén et al. 1998)
Conclusions: Effects of solvent exposure on the reproductive health of men • Ethylene glycol ethers harmful for male reproductive system • Carbon disulfide related to decreased libido and potency in men • No clear association between solvent exposure and decreased fertility • Evidence on the effects of paternal exposure on pregnancy outcome inconclusive, although suggestive associations noted
Hazard assessment • Exposure may be high for example in spray painting, shoe making, degreasing, printing and dry cleaning • Assessment of solvent exposure with industrial hygienic measurements or biological monitoring • In some countries the guidelines recommend that solvent exposure should not exceed 10% of the threshold limit value during pregnancy
References on solvent exposure and reproductive health • McMartin KI, Chu M, Kopecky E, Einarson TR, Koren G. Pregnancy outcome following maternal organic solvent exposure: a meta-analysis of epidemiologic studies. Am J Ind Med 1998;34:288-292. • Tas S, Lauwerys R, Lison D. Occupational hazards for the male reproductive system. Crit Rev Toxicol 1996;26:261-307. • Lindbohm M-L. Effects of parental exposure to solvents on pregnancy outcome. J Occup Environ Med 1995;37:908-914.