Exposure to everyday pollutants may trigger early menopause, according to a new study from the Washington University School of Medicine in St. Louis, which revealed that women exposed to high levels of chemicals found in plastics, personal-care products, common household items, and the environment experience menopause two to four years earlier than women exposed to lower levels of these chemicals.
The researchers looked at levels in blood and urine of 111 chemicals that are suspected of interfering with the natural production and distribution of hormones in the body. While several smaller studies have examined the link between so-called endocrine-disrupting chemicals and menopause, the new research is the first to broadly explore the association between menopause and individual chemicals on a large scale, using a nationally representative sample of patients across the United States.
“Chemicals linked to earlier menopause may lead to an early decline in ovarian function, and our results suggest we as a society should be concerned,” said senior author Dr. Amber Cooper, MD, an assistant professor of obstetrics and gynecology.
A decline in ovarian function not only can adversely affect fertility but also can lead to earlier development of heart disease, osteoporosis and other health problems. Other problems already linked to endocrine-disruptors include certain cancers, metabolic syndrome and, in younger females, early puberty.
Fifteen chemicals identified as potential contributors to early menopause
In the study, Dr. Cooper and researchers at the University of Missouri-Kansas City School of Medicine and the Wadsworth Center at the State University of New York at Albany analyzed data collected from 1999-2008 as part of the National Health and Nutrition Examination Survey, conducted by the U.S. Centers for Disease Control and Prevention.
The survey included data from 31,575 people, including 1,442 menopausal women who had been tested for levels of endocrine-disrupting chemicals. The average age of these women was 61, and none was using estrogen-replacement therapies or had had surgery to remove ovaries. The survey was designed so that the women who had undergone chemical testing would represent a population of almost 9 million menopausal women.
The women’s blood and urine samples were analyzed for exposures to 111 mostly man-made chemicals, which included known reproductive toxins and/or those that take more than a year to break down. Chemicals from the following categories were analyzed in the survey:
- dioxins/furans (industrial combustion byproducts)
- phthalates (found in plastics, common household items, pharmaceuticals and personal-care products including lotions, perfumes, makeup, nail polish, liquid soap and hair spray)
- phytoestrogens (plant-derived estrogens)
- polychlorinated biphenyls (PCBs, coolants)
- phenolic derivatives (phenols, industrial pollutants)
- organophosphate pesticides (a common type of insecticide used on crops)
- surfactants (found in laundry and dishwashing detergents, household cleaners, and personal-care products)
- polycyclic aromatic hydrocarbons (combustion products)
The researchers identified 15 chemicals — nine PCBs, three pesticides, two phthalates, and one furan (a toxic chemical) — that warrant closer evaluation because they were significantly associated with earlier ages of menopause and potentially have detrimental effects on ovarian function.
“Earlier menopause can alter the quality of a woman’s life and has profound implications for fertility, health and our society,” Dr. Cooper said. “Understanding how the environment affects health is complex. This study doesn’t prove causation, but the associations raise a red flag and support the need for future research.”
An emerging public health concern
The World Health Organization recognizes endocrine-disrupting chemicals as an emerging global public health threat, cautioning that the list of known endocrine-disruptors is only the ‘tip of the iceberg’. Comprehensive testing methods are required to identify other possible endocrine-disruptors, their sources, and routes of exposure, WHO says.
It will also be important to consider new sources of these chemicals linked to advances in industry and technology. For instance, researchers recently discovered that hydraulic fracturing, or fracking, can leak endocrine-disrupting chemicals into the water supply.
“Many of these chemical exposures are beyond our control because they are in the soil, water and air,” Dr. Cooper said. “But we can educate ourselves about our day-to-day chemical exposures and become more aware of the plastics and other household products we use.”
For example, Dr. Cooper recommends that people microwave food in glass or paper containers instead of in plastic and try to learn more about the ingredients in cosmetics, personal-care products and food packaging they use every day. Although many of the chemicals included in the study have been banned from U.S. production because of their negative health effects, they still are produced globally and are pervasive in the environment. Other steps you can take to reduce your exposure to endocrine-disrupting chemicals include:
- Buy organic food whenever possible.
- Avoid using pesticides in your home or yard, or on your pet — use baits or traps instead, keeping your home especially clean to prevent ant or roach infestations.
- Find out if pesticides are used in your child’s school or day care center and campaign for non-toxic alternatives.
- Avoid fatty foods such as cheese and meat whenever possible (these chemicals are stored in fat, so high-fat foods have a higher chemical content).
- If you eat fish from lakes, rivers, or bays, check with your state to see if they are contaminated.
- Do not give young children soft plastic teethers or toys, since these leach potential endocrine disrupting chemicals.
- Support efforts to get strong government regulation of and increased research on endocrine disrupting chemicals.