Solvent Exposure and Heart Birth Defects
Workplace exposure to organic solvents has been linked to several types of birth heart defects as shown by research published online in Occupational and Environmental Medicine. Organic solvents are widely used for dissolving or dispersing substances, such as fats, oils, and waxes, as well as in chemical manufacturing. They are found in paints, varnishes, adhesives, degreasing/cleaning agents, dyes, polymers, plastic, synthetic textiles, printing inks and agricultural products. The authors looked for associations between 15 categories of congenital heart defects and exposure to types of organic solvents known to be relatively common in the workplace. These solvents included chlorinated solvents; aromatic solvents; and a mix of C10 or higher hydrocarbons known as Stoddard solvent.
Common uses for organic solvents are in dry cleaning (e.g., tetrachloroethylene), as paint thinners (e.g., toluene, turpentine), as nail polish removers and glue solvents (acetone, methyl acetate, ethyl acetate), in spot removers (e.g., hexane, petrol ether), in detergents (citrus terpenes), in perfumes (ethanol), nail polish and in chemical synthesis.
General health hazards associated with solvent exposure include toxicity to the nervous system, reproductive damage, liver and kidney damage, respiratory impairment, cancer, and dermatitis.
Industrial hygienists in the new study assessed the levels of workplace exposure to organic solvents in 5000 women from across the US, from one month before conception through to the first three months of pregnancy (first trimester). All their babies were delivered between 1997 and 2002, and included stillbirths and pregnancy terminations. All the women were taking part in the National Birth Defects Prevention Study, an ongoing population based study that is exploring risk factors for birth defects.
According to the previous expert consensus approach, two types of congenital heart defects were associated with exposure to any solvent and to chlorinated solvents, although these associations were only of borderline significance. The published evidence approach indicated several additional associations between congenital heart defects and exposure to organic solvents. The authors conclude that their results suggest that exposure to organic solvents in the period from one month before conception to early pregnancy is a potential risk factor for several types of heart defects at birth.
Some of their findings back up those of other researchers, while the rest are new, they say. But they caution: "Despite the strengths of this analysis, the results do not allow for the drawing of definitive conclusions on specific exposure-congenital heart defect combinations."
For further information see Birth Defect,
Solvent image via Wikipedia.