Environmental Impacts on Reproductive Health – Chemical Exposures in the Workplace
(Published January 2010) This chapter focuses on exposures to synthetic chemicals in the workplace. Workplace exposure is an important way that patients come into contact with reproductive and developmental toxicants. Workplace exposure to such chemicals …
(Published January 2010)
This chapter focuses on exposures to synthetic chemicals in the workplace.
Workplace exposure is an important way that patients come into contact with reproductive and developmental toxicants. Workplace exposure to such chemicals is not limited to employees of chemical manufacturing plants or other facilities that directly involve the use of chemicals. Exposure to substances with developmental and reproductive health effects can occur in all types of occupations, including but not limited to health care, farming, nail and hair styling, professional home cleaning, and landscaping. Individuals also may be exposed in the home or through hobbies to the same reproductive and developmental toxicants that are found in the workplace. For example, solvents, which increase the risk of adverse pregnancy outcomes, are used in a number of workplace settings and are also found in a variety of consumer products such as paint strippers and hobby-related products such as paint or ink.1
Benzene:
An Example of a Reproductive
and Developmental Toxicant
Known reproductive toxicants include heavy metals such as methylmercury and chemical compounds such as benzene. Benzene is an aromatic liquid or vapor. In the past, it was used as a solvent in various materials including inks, glues, and paint remover. It is now used as a precursor in the synthesis of plastics and dyes. In addition, gasoline contains benzene. For this reason, workers who clean or remove underground fuel storage tanks may be exposed to the toxicant. Exposure to benzene has been linked to aplastic anemia, cancer, and adverse reproductive effects.3 In the United States, other solvents, such as toluene and naphthalene, are used increasingly to replace benzene. Because of the widespread use of these solvents, individuals may encounter them in a variety of settings, including the workplace and the home. For example, gasoline, household aerosols, paints, paint thinners, adhesives, nail polish remover, and solvent-based cleaning products may contain toluene.4 Naphthalene is used in moth repellents, coal tar products, and certain dyes and inks.5
The Reproductive Health Impact of Chemical Exposures
A number of adverse reproductive effects can occur as a result of exposure to toxicants in the workplace, and exposure to toxicants can affect the reproductive health fertility of both men and women. For example, women exposed to hazardous substances may experience hormonal changes that can lead to subfertility, and men may exhibit abnormal sperm morphology or a reduced sperm count.2
Many occupations may result in exposure to reproductive toxicants. Some of the occupations that are more likely to involve exposure are obvious—pest control technicians, for example. Table 5 lists examples of occupations that have a higher risk for exposures to toxic substances. Individuals in these occupations should be made aware of the potential for adverse effects and encouraged to take steps to mitigate exposure.
Other occupations with potential for exposure are less obvious. In fact, it is impossible to predict with complete accuracy which work settings are likely to exposure individuals to reproductive toxicants; these chemicals could be present in settings that one wouldn't expect, such as a patient's home or an academic or office building. For this reason, it is important for patients to consider whether they are or have been exposed to chemicals, fumes, or potentially problematic substances, no matter their workplace setting.
Providers must weigh the benefits of intervention with the potential challenges associated with job loss or discrimination. An incidental exposure may not be of concern when viewed against the consequences of a job loss. However, significant exposure to a toxicant must be addressed and mitigated. If a provider identifies a reproductive or developmental hazard, he or she should refer the patient to an occupational health expert who can assess the hazard and provide knowledgeable counseling about the risks and the individual's legal rights. By law, employers are responsible for maintaining a safe work environment and must provide information and education about hazardous chemicals in the workplace. Providers can inform patients of these rights and refer them to occupational health experts and resources for additional help and information.
Table 5: Examples of Occupations with Higher Risk of Exposure to Toxicants3
Assembling & Fabrication
Crop & Livestock Production
Engineering, Sciences & Education
Extractive Industries (i.e., mining)
Farm Work
Logging, Forest & Conservation
Material Moving
Metalworking & Plasticworking
Miscellaneous Production
(e.g., electronics manufacture)
Nail and Hair Salons
Textile, Apparel & Furnishings
Utilities & Transportation
Case Study: Jennifer*
Jennifer is a nulliparous, 30-year-old healthy woman who presents to your office for her annual well-woman exam. She was recently married and is contemplating pregnancy within the next year. She has no complaints except for occasional headaches, which occur sometimes at work but never on weekends.
Jennifer has worked as a lab technician at a local polymer manufacturer for the past 6 years. She is concerned about possible chemical exposure at work. For protective equipment she uses eye protection, an apron, and latex gloves. There is no ventilation hood in the lab. The primary chemical she works with is N-methylpyrrolidone (NMP), a chemical used to dissolve a wide range of other chemicals. She is exposed to NMP on a weekly, and often daily, basis.
Jennifer's exam is normal. The pregnancy test that you order is negative. You pull up the material safety data sheet (MSDS) for NMP online, which you review with Jennifer. The MSDS mentions no adverse reproductive effects, and Jennifer is relieved. However, knowing that MSDS entries are often incomplete and inaccurate with regard to information on the reproductive effects of the chemical, you investigate NMP in more detail on the Internet. You learn that in 2001, NMP was listed as a known reproductive toxicant in the state of California on the basis of animal studies.6 You search the developmental and reproductive toxicology database at the TOXNET Web site and find several entries, including a case of a pregnancy loss in a lab technician exposed to NMP.
On the basis of the information from the Internet and the toxicology database, you refer Jennifer to an occupational health specialist. You receive a note from the specialist after Jennifer's consultation. She has recommended the use of additional safety precautions at Jennifer's workplace, including a ventilator hood, a well-fitted respirator, neoprene rather than latex gloves (the former are more resistant), and continued use of the apron and eye protection.
The occupational health specialist asks you to explore with Jennifer the options for transferring out of the lab to a less toxic work environment, bearing in mind her legal rights and the potential for job loss or discrimination. You write a letter to Jennifer's employer identifying NMP as a potential reproductive toxicant, highlighting the importance of avoiding reproductive toxicants, and the need to transfer Jennifer to a job without such exposure while she is trying to get pregnant and during pregnancy.
The employer transfers Jennifer to a position with less toxic exposure and invests in additional safety equipment for Jennifer and other employees. Had no other jobs been available, Jennifer might have decided to continue in the same job with improved protection. After the transfer, Jennifer's headaches resolve.
This case illustrates that exposures to reproductive toxicants can occur at the workplace. With understanding and appropriate information, health care providers can advocate for their patients and make specific workplace recommendations that reduce the risk of exposure to reproductive toxicants.
*Case study adapted from GENERATIONS AT RISK: REPRODUCTIVE HEALTH AND THE ENVIRONMENT, published by The MIT Press.7
Counseling Patients on Exposures to Industrial Chemicals
When counseling patients about exposures to industrial chemicals, providers should:
Ask about the patient's occupation, including the setting, job-related tasks, and any known chemical exposures.
Ask about potential chemical exposures, including specific questions to uncover exposures that the patient might mistakenly believe are insignificant (e.g., "Does your worksite use fumigation to deal with pests?").
Recommend that patients try to become familiar with all chemicals used or encountered in their work setting and learn about the potentially toxic properties of these chemicals.
Direct patients to appropriate sources of information about chemicals (see Resources for Providers and Patients chapter).
Instruct patients on steps to take to mitigate exposure or refer them to an occupational health expert who can suggest exposure-reducing strategies (e.g., substitute a safer chemical, wash exposed skin, change from work clothes before leaving the workplace, wash any exposed clothes separately to prevent contamination of other clothing).
Check that patients have access to and are using appropriate protective gear.
Advise patients to avoid contact with clothes that others in the household wear home if there is a potential for toxicant exposure.
Advise patients to take extra care to avoid exposure if they are pregnant or planning pregnancy, because standard personal protective equipment may not be sufficient to guard from exposure to reproductive toxicants.
Additional Provider Resources on Industrial Chemicals:
Providers should use available resources to investigate the toxic properties of specific industrial chemicals to which their patients are exposed.
For general toxicant information:
The HazMat database: provides information about symptoms and conditions associated with toxicants and the occupational activities most likely to lead to exposure.
Material safety data sheet (MSDS): these sheets provide general information about the health effects of exposure to a particular chemical. However, the MSDS entries are often incomplete and inaccurate with regard to information on the reproductive effects of the chemical; providers should not rely on the lack of mention of reproductive toxicity in the MSDS as an indication of safety. Providers and patients should check product labels (with the caveat that these may be inaccurate or incomplete) and toxicology databases for information about potential reproductive effects.
For information specific to reproductive toxicants:
California Proposition 65 Web site: List of chemicals recognized to cause cancer or reproductive toxicity; approximately 800 chemicals are listed
Environmental Health and Toxicology Web site of the National Library of Medicine: Educational resources and links to databases that identify substances known to cause reproductive or other toxicity
ReproTox: An online database for providers and consumers that presents information on more than 5,000 agents and exposures and their reproduction-related effects
ToxNet Web site of the National Library of Medicine: Links to several databases that identify substances known to cause reproductive or other toxicity
The next chapter addresses some chemicals in plastics, including bisphenol A, an endocrine-disrupting chemical in some plastic bottles and in the lining of cans used for food and beverages.
McDiarmid MA, Gehle K. Preconception brief: occupational/environmental exposures. Matern Child Health J. 2006;10:S123–8.
Centers for Disease Control and Prevention. The effects of workplace hazards on male reproductive health. 1997. Available at: http://www.cdc.gov/niosh/malrepro.html. Accessed October 6, 2009.
HazMat database. Last updated September 2009.
Agency for Toxic Substances and Disease Registry. Toluene toxicity exposure pathways. Case study. 2001.
Agency for Toxic Substances and Disease Registry. Naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene. ToxFAQs.™ 2005.
California Office of Environmental Health Hazard Assessment. Proposition 65. Available at: http://www.oehha.ca.gov/prop65/prop65_list/091009list.html. Accessed January 7, 2010.
Schettler T, Solomon G, Valenti M, Huddle A. Generations at Risk: Reproductive Health and the Environment. Boston, MA: MIT Press. 1999.
Brochures for Patients – Guia de la mujer para Comprender el VPH y el Cancer Cervical
Curricula Organizer for Reproductive Health Education (CORE)