Health and Safety: Zapped - Reproductive Hazards in the Workplace (3/94)

MISCARRIAGES, birth defects, infertility: scientists are still studying the extent to which these are caused by occupational and environmental exposures. We need to undertake further research on those chemicals and conditions which have harmful reproductive effects — and then find ways of reducing our exposure to them.

Last September the federal Agency for Toxic Substances and Disease Registry (ATSDR) released an important study of chemicals which can harm male and female reproductive systems and the developing fetus. Because these chemicals and agents can often be found in the workplace and in the environment, we need to know more about them so we can prevent or limit our exposure.

The report is entitled Reproductive and Developmental Hazards, ATSDR Case Study in Environmental Medicine No. 29. The authors are Drs. Laura Welch and Maureen Paul, both national leaders in the field of occupational and environmental medicine. (ATSDR, which published the report, is a federal research agency which advises the U.S. Environmental Protection Agency.)

In their introduction to the study, the authors summarize some basic facts about fertility and childbirth in the United States:

"The extent to which environmental or occupational exposures affect these statistics is unknown," the authors state. However, some chemicals and conditions which we know cause harmful reproductive effects have been identified. Below is a list of exposures which can harm the male reproductive system (Table I):

Table I Exposures Which May Cause Male Reproductive Disorders
Agent	Effects
Carbon disulfide	Decreased sperm counts, decreased sperm movement
Chloroprene	Decreased sperm movement, decreased sexual drive
DBCP (Dibromo-chloropropane)	Decreased sperm count, hormonal changes
Estrogens	Decreased sperm count
Heat stress	Decreased sperm count
Lead	Decreased sperm count
Ionizing radiation	Decreased sperm count

As readers know, exposure to lead and ionizing radiation are common in U.S. industry, as is serious heat exposure. Chloroprene, another chemical in Table I, is widely used in the rubber and tire industries and DBCP is a common pesticide. The harm which chemicals do to the male sperm can be relatively easily studied in the laboratory, using sperm samples taken after chemical exposure. This cannot normally be done for chemical effects on the female reproductive system, since a woman’s eggs are permanently stored in her body. However, statistical studies can reveal harmful chemical effects on female reproduction (Table II):

Table II Exposures Which May Cause Female Reproductive Effects
Agent	Effects
Lead	Spontaneous abortion, premature births, birth defects
Organic mercury	Central nervous system birth defects, cerebral palsy
Great physical stress	Premature births
PCBS (Poly-chlorinated biphenyls)	Low birth weights
Ionizing radiation	Menstrual disorders, birth defects (many types), childhood cancers

Finally, the authors identify some chemicals, drugs and disease agents which can harm the embryo while it is developing within the mother (Table III).

Table III
Exposures Which May Harm the Developing Fetus

Chemicals/Drugs

Infectious Agents

Alcohol
Some anti-thyroid drugs
Chlorobiphenyls
Coumarin anti-coagulant drugs
Lithium
Organic mercury
Tetracyclines
Thalidomide
Ionizing radiation

Hepatitis B virus

Herpes Simplex virus

Rubella virus

Syphilis

Chicken pox virus

For these workplace and environmental health problems, we seek to prevent all unnecessary exposures. If such exposures cannot be eliminated, they can and should be controlled. If you are exposed these chemicals and are planning to have a child, you should talk with your doctor in advance, and discuss whether any preventive health measures can be taken.

Zapped: Reproductive Hazards In the Workplace

Zapped: Reproductive
Hazards In the Workplace