Menstrual products as a source of environmental chemical exposure: A review from the epidemiologic perspective

Overview

Upson, Shearston, and Kioumourtzoglou reviewed menstrual products as a potential source of environmental chemical exposure from an epidemiologic perspective. The paper is secondary evidence: it summarizes product-chemistry studies and three human biomonitoring studies, but it does not generate new product concentration data. Its metal-specific value is context around Singh et al. 2019 whole-blood cadmium, lead, and mercury in tampon users, not primary tampon occurrence.

Key numbers

• Use-pattern framing: the review says menstrual bleeding occurs on average every 24-38 days from menarche to menopause. Under assumptions of 13 cycles per year, 5 bleeding days per cycle, and 4 menstrual products per day, menstruators could use more than 10,000 menstrual products over a lifetime.
• U.S. market framing: tampon and menstrual-pad sales exceeded $2.8 billion in 2018, with nearly 600 million units sold.
• Review inclusion: the authors restricted the review to studies with enough information to understand scientific methods and results. They excluded risk assessments that did not measure chemicals in menstrual products and methods papers that did not provide product concentration values.
• Product-chemistry evidence: the review says 23 studies measured chemicals in menstrual products; all reviewed product studies detected environmental chemical concentrations, though risk conclusions differed across studies.
• Exposure assessment: of the 23 product studies reviewed, 13 conducted exposure assessment and risk characterization. Over half estimated average daily exposure over an average month (30 days) or over a lifetime rather than only on product-use days.
• Human epidemiology evidence: only 3 epidemiologic studies had investigated menstrual-product use and environmental chemical concentrations measured in women at the time of the review.
• Phthalate epidemiology: Branch et al. 2015 used NHANES 2001-2004 data in women ages 20-49 years (n=739 unweighted) and reported that vaginal douche users had MEP concentrations 52% higher than non-users (95% CI: 19%, 94%). The review reports no associations for tampon or sanitary-napkin use in that study.
• VOC epidemiology: Ding et al. 2020 used NHANES 2001-2004 data in women ages 20-49 years (n=2432 unweighted) and reported 36% higher whole-blood ethylbenzene in feminine-powder users (95% CI: 0% to 83%) and 81% higher 1,4-DCB in women who douched two or more times in the past six months (95% CI: 2% to 221%).
• Metal epidemiology: Singh et al. 2019 studied premenopausal women ages 18-44 years in the Western New York BioCycle Study (n=259) and evaluated tampon use against whole-blood cadmium (Cd), lead (Pb), and mercury (Hg). Any tampon use during up to two menstrual cycles was associated with a 25% higher geometric mean mercury concentration, with adjusted ratio 1.25 and 95% CI: 0.93-1.68; no associations were observed with cadmium or lead concentrations.
• Metal-product evidence gap at the time: the review states that no prior studies had evaluated the presence of metals in tampons before the Singh et al. biomonitoring work.
• Microbiome/TSS context: the review describes the Rely tampon toxic-shock-syndrome case example, including a reported 10-15% case-fatality ratio and possible mechanisms involving oxygen, pH, S. aureus, menses, and lack of antibodies to toxin.
• Research recommendations: the paper recommends empirical data on vaginal and vulvar absorption, epidemiologic research with exposure measurements timed with menses, consideration of menstrual products in gynecologic-condition studies, and publication of NGO/consumer-organization testing in searchable scientific venues.

Methods (brief)

This is a peer-reviewed narrative review. The authors summarized studies in which enough information was available to evaluate scientific methods and results, drawing from peer-reviewed articles, government reports, consumer-association work, and environmental-organization studies. They grouped the evidence into product-chemistry studies, exposure/risk characterizations, and three epidemiologic studies linking menstrual-product use to measured environmental chemicals in women. The paper does not report a formal PRISMA search, pooled meta-analysis, new laboratory method, LOD/LOQ values, or new product sampling.

Speciation: cadmium and lead are reported as whole-blood metals in a cited epidemiologic study. Mercury is reported as whole-blood mercury; the review does not identify methylmercury, so this page uses tHg and does not infer methylmercury (MeHg).

Implications

Microbiome: The paper discusses menstrual toxic shock syndrome, S. aureus, vaginal pH, oxygenation, menstrual fluid, and the vaginal microbiome as exposure-context mechanisms. It does not report a new microbiome measurement.

Related evidence

• Menstrual tampons (scented/unscented; applicator tested as distinct component)
• Menstrual pads (disposable, panty liners, intralabial pads, reusable menstrual pads)
• Feminine wipes/towelettes
• Feminine deodorants (leave-on and rinse-off)
• Douches and vaginal irrigation solutions/apparatus components
• Dusting/talc powders (adult)
• Cadmium
• Lead
• Mercury, Total

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.