Research & Sources

~8,000 annual US bladder cancer cases attributable to disinfection byproducts in tap water — roughly 1 in 10 of all bladder cancer cases in the US.

Peer-ReviewedWeisman RJ, Heinrich A, Letkiewicz F, et al. “Estimating national exposures and potential bladder cancer cases associated with chlorination DBPs in U.S. drinking water.” Environmental Health Perspectives, 2022; 130(8):087002. Read study →

100,000+ lifetime cancer cases could be attributed to carcinogenic chemicals in tap water.

Peer-ReviewedEvans S, Campbell C, Naidenko OV. “Cumulative risk analysis of carcinogenic contaminants in United States drinking water.” Heliyon, 2019; 5(9):e02314. Read study →

PFOA — the most common PFAS in tap water — is classified as a confirmed human carcinogen (Group 1) by the World Health Organization’s International Agency for Research on Cancer. The same classification as asbestos, tobacco smoke, and benzene.

GovernmentInternational Agency for Research on Cancer (IARC). IARC Monographs Volume 135: Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS). November 2023. View monograph →

200M+ Americans estimated to have PFAS (forever chemicals) in their tap water.

Peer-ReviewedAndrews DQ, Naidenko OV. “Population-Wide Exposure to Per- and Polyfluoroalkyl Substances from Drinking Water in the United States.” Environmental Science & Technology Letters, 2020; 7(12):931–936. Read study →

AnalysisEnvironmental Working Group / Agency for Toxic Substances and Disease Registry (ATSDR). View map →

PFAS detected in 39 of 101 U.S. bottled water samples — the first peer-reviewed survey of PFAS in U.S. bottled water. Ultrashort-chain PFAS, measured in bottled water for the first time, accounted for 42% of detected mass, found almost exclusively in spring-water products.

Peer-ReviewedChow SJ, Ojeda N, Jacangelo JG, Schwab KJ. “Detection of ultrashort-chain and other per- and polyfluoroalkyl substances (PFAS) in U.S. bottled water.” Water Research, 2021; 201:117292. Read study →

118 of 120 locations tested across the US had lead, arsenic, or PFAS above recommended maximum levels.

AnalysisConsumer Reports / The Guardian, 2021. Read investigation →

PFAS exposure linked to up to 40% reduced fertility in women.

Peer-ReviewedCohen NJ, Yao M, Midya V, et al. “Exposure to perfluoroalkyl substances and women’s fertility outcomes in a Singaporean population-based preconception cohort.” Science of the Total Environment, 2023; 873:162267. Read study →

Microplastics in arterial plaque associated with 4.53× increased risk of heart attack, stroke, or death over 34 months of follow-up. The most-detected polymer was polyethylene.

Peer-ReviewedMarfella R, et al. “Microplastics and Nanoplastics in Atheromas and Cardiovascular Events.” New England Journal of Medicine, 2024; 390(10):900–910. Read study →

3–5× higher microplastic accumulation in the brains of dementia patients vs. healthy controls. Brain microplastic concentrations rose 47% from 2016 to 2024 — the highest of any organ studied.

Peer-ReviewedNihart AJ, et al. “Bioaccumulation of Microplastics in Decedent Human Brains.” Nature Medicine, 2025; 31(4):1114–1119. Read study →

Microplastics found in 94% of US tap water samples.

AnalysisTyree C, Morrison D. “Invisibles: The Plastic Inside Us.” Orb Media, 2017. Read report →

22× more microplastics ingested from bottled water vs. tap. Bottled water drinkers consume ~90,000 additional particles per year.

Peer-ReviewedCox KD, et al. “Human Consumption of Microplastics.” Environmental Science & Technology, 2019; 53(12):7068–7074. Read study →

240,000 nanoplastics per liter of bottled water.

Peer-ReviewedQian N, et al. “Rapid single-particle chemical imaging of nanoplastics by SRS microscopy.” Proceedings of the National Academy of Sciences (PNAS), 2024; 121(3):e2300582121. Read study →

Microplastics found in 100% of human testicular tissue samples at an average of 329 µg/g — three times higher than placental tissue. Plastics in human reproductive organs at levels never before documented.

Peer-ReviewedHu CJ, et al. “Microplastic presence in dog and human testis and its potential association with sperm count and weights of testis and epididymis.” Toxicological Sciences, 2024; 200(2):235–240. Read study →

Pharmaceuticals and hormones detected in 80% of U.S. streams sampled across 30 states — the most-cited paper in Environmental Science & Technology history.

Peer-ReviewedKolpin DW, et al. “Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999–2000: A national reconnaissance.” Environmental Science & Technology, 2002; 36(6):1202–1211. Read study →

Pharmaceuticals detected in 1,052 sampling sites across 258 rivers in 104 countries — the largest geographic study of pharmaceutical contamination ever conducted. More than a quarter of all locations had pharmaceutical levels posing a threat to environmental or human health.

Peer-ReviewedWilkinson JL, et al. “Pharmaceutical pollution of the world’s rivers.” PNAS, 2022; 119(8):e2113947119. Read study →

Pharmaceutical residues including birth control and antidepressants detected in city drinking water.

AnalysisHarvard Health Publishing. Read article →

Sperm counts in Western men have declined over 50% since 1973.

Peer-ReviewedLevine H, et al. “Temporal trends in sperm count: a systematic review and meta-regression analysis.” Human Reproduction Update, 2017; 23(6):646–659. Read study →

Endocrine-disrupting compounds (EDCs) in tap water linked to hormone disruption, infertility, and developmental issues.

Peer-ReviewedKasonga TK, et al. “Endocrine-disruptive chemicals as contaminants of emerging concern in wastewater and surface water.” npj Clean Water, 2023; 6:75. Read study →

Synthetic estrogen at trace concentrations (5–6 ng/L) caused near-total collapse of a fish population in a 7-year whole-lake experiment. Up to 44% of male minnows became intersex. Catch rates dropped over 99%. Direct evidence that trace pharmaceutical concentrations are biologically active.

Peer-ReviewedKidd KA, et al. “Collapse of a fish population after exposure to a synthetic estrogen.” PNAS, 2007; 104(21):8897–8901. Read study →

The Endocrine Society’s scientific consensus on endocrine-disrupting chemicals. 150-page review by 8 authors. EDCs “convincingly associated” with obesity and diabetes, female and male reproductive disease, hormone-sensitive cancers, prostate disease, thyroid dysfunction, and neurodevelopmental disorders. The single highest-authority document on EDC science.

Peer-ReviewedGore AC, et al. “EDC-2: The Endocrine Society’s Second Scientific Statement on Endocrine-Disrupting Chemicals.” Endocrine Reviews, 2015; 36(6):E1–E150. Read study →

Endocrine disruptor exposure costs the European Union an estimated €157 billion per year in healthcare costs and lost productivity — roughly 1.23% of EU GDP. The single most-cited economic burden statistic in the entire EDC literature.

Peer-ReviewedTrasande L, et al. “Estimating Burden and Disease Costs of Exposure to Endocrine-Disrupting Chemicals in the European Union.” Journal of Clinical Endocrinology & Metabolism, 2015; 100(4):1245–1255. Read study →

Endocrine disruptors in water and their effects on the reproductive system.

Peer-ReviewedGonsioroski A, Mourikes VE, Flaws JA. “Endocrine Disruptors in Water and Their Effects on the Reproductive System.” International Journal of Molecular Sciences, 2020; 21(6):1929. Read study →

251 million Americans — 81% of the U.S. population served by community water systems — receive water from systems that detected lead at or above 1 ppb, the American Academy of Pediatrics’ recommended maximum for children.

AnalysisNatural Resources Defense Council (NRDC), 2025. Read report →

Lead detected in 43% of schools that tested their water.

GovernmentU.S. Government Accountability Office (GAO), 2020. Read report →

How safe is our drinking water? Comprehensive investigation into US tap water quality.

Consumer Reports. Read investigation →

Scientists thought Parkinson’s was in our genes. It might be in the water.

WIRED. Read article →

Water expert warns Americans of ‘chemical cocktail’ in dangerous chemically-tainted tap water.

New York Post, 2025. Read article →

Forever chemicals are in your drinking water: how worried to be and what to do about it.

Fortune, 2025. Read article →

63 million Americans exposed to unsafe drinking water in the past decade.

News21 investigation. Read investigation →

April 2, 2026: The EPA designated pharmaceuticals as a priority drinking water contaminant for the first time in the agency’s 30-year history, simultaneously releasing health benchmarks for 374 pharmaceutical compounds. These are guidance values, not enforceable limits. Zero federal Maximum Contaminant Levels exist for any pharmaceutical in U.S. drinking water.

GovernmentU.S. Environmental Protection Agency. Draft Contaminant Candidate List 6 (CCL 6). View EPA filing →

April 2, 2026: The EPA designated microplastics as a priority drinking water contaminant for the first time, on the same Contaminant Candidate List 6. No federal limits, no enforceable standards — only guidance that microplastics warrant federal attention.

GovernmentU.S. Environmental Protection Agency. Draft Contaminant Candidate List 6 (CCL 6). View EPA filing →

April 2024: The EPA finalized the first national drinking water standards for PFAS in U.S. history — a 28-year regulatory achievement. Maximum Contaminant Levels: 4 ppt for PFOA, 4 ppt for PFOS, 10 ppt each for PFNA, PFHxS, and GenX. PFAS were first added to the EPA’s Contaminant Candidate List in 2009; it took 15 years to set enforceable limits.

GovernmentU.S. Environmental Protection Agency. Final PFAS National Primary Drinking Water Regulation. View EPA regulation →

May & September 2025: The EPA rolled back the 2024 PFAS standards. PFOA and PFOS compliance was delayed from 2029 to 2031. The EPA filed a motion to vacate enforceable limits for four of the six regulated PFAS compounds (PFNA, PFHxS, GenX, PFBS) entirely. The replacement chemicals industry adopted after PFOA and PFOS were phased out are no longer regulated.

GovernmentU.S. Environmental Protection Agency administrative actions, May & September 2025. View EPA actions →

Dr. Betsy Southerland, Former Director, Office of Science and Technology, EPA Office of Water:

“If you don’t want to continue drinking these toxic PFAS chemicals for years into the future, you need to buy a filter to protect yourself because EPA will not protect you.”

Via Environmental Protection Network, September 2025 PFAS rollback statement. Read statement →