Can environmental exposures cause congenital anomalies?

There is limited evidence that environmental exposures may cause congenital anomalies. Much of this evidence concerns anomalies associated with living close to a hazardous waste site.

Several studies suggest that parents living close to a hazardous waste site may have an increased risk for having children with various congenital anomalies, especially those involving the nervous system and cardiovascular system. [2-5] However, not all studies support this relationship. [6] Furthermore, some authors have raised objections to the quality of evidence provided by such studies. [8-9]

One study suggests that living in a highly industrialized area may increase risk of having children with congenital anomalies. [10]

We also have some evidence that individual environmental exposures may be linked with congenital anomalies. Each of these exposures (pesticides, drinking water contaminants, industrial solvents) will be discussed separately below.

Pesticides:
These are chemical compounds used to kill pests, including insects, rodents, worms, weeds, and fungi. To learn more about pesticides, click here.

Several occupational studies suggest that parents exposed to pesticides in agricultural settings may have increased risk of having children with various congenital anomalies, most notably those of the nervous system and musculoskeletal system. [12-16] However, not all studies support this relationship. [18]

One case study suggests that mothers exposed to the organophosphate pesticide Dursban may have increased risk of children with congenital anomalies. [11] However, this does not show that Dursban caused the congenital anomalies.

Drinking water contaminants:
Drinking water contaminants of interest include disinfection by products (DBPs) and organic solvents. To learn more about DBPs, click here. Solvents are discussed below.

One study suggests that mothers exposed to DBPs may have an increased risk of having children with neural tube defects (problems with the developing spinal cord). [18]

Several studies suggest that mothers drinking tap water have increased risk of having children with congenital anomalies, especially of the cardiovascular system and nervous system. [19-22] However, the chemical exposures in each study may have been different. Thus, these studies do not clearly point to any particular chemical.

Industrial Solvents:
Solvents are liquids that can dissolve other substances. Industrial solvents are often used for cleaning machinery or other materials.

One study suggests that parents living near industries releasing solvents into the air had increased risk of having children with congenital anomalies of the nervous system. [6]

One study suggest that mothers exposed to various industrial solvent in contaminated drinking water have an increased risk of having children with congenital anomalies of the cardiovascular and nervous systems. [19]

Though these studies suggest a possible association between solvents and congenital anomalies, they do not clearly show that solvents cause congenital anomalies.