Coal operations and cancer in the US: A systematic review - May 2026

Public Health https://doi.org/10.1016/j.puhe.2026.106311 PDF behind paywall

Objectives; Soon after declaring its first national energy emergency in January 2025, the US government committed to increasing coal production and use. Coal operations (e.g., mining, processing, burning, waste management) not only contribute to climate change but also have environmental and public health consequences that may influence cancer risk and outcomes. The aim of this systematic review is to synthesize published evidence on cancer risk and outcomes associated with exposure to coal operations in the US.

Study design

Systematic review.

Methods: We searched PubMed, Embase, Scopus, and CINAHL for quantitative studies published in English between January 1980 and April 2025 evaluating any type of exposure to coal operations and cancer outcomes in the US. Grey literature, non-epidemiological studies, and studies that used cancer cases as controls were excluded. Risk of bias was assessed using ROBINS-E.

Results : The search identified 3065 unique articles, 45 of which were included. All 18 studies that evaluated residential exposures and cancer mortality found statistically significant associations. Similarly, all occupational studies published after 2003 found statistically significant associations with increased cancer mortality. Competing risks, healthy worker bias, and ecological fallacy were the most common limitations of studies included in the review. Findings from 19 studies evaluating either residential or occupational exposure to coal operations and cancer incidence were mixed, and no significant association was found with residential exposure in the single study of cancer-related hospitalizations. Surveillance and research infrastructure supported by the US federal government was used in 82% of studies evaluating the association between coal operations and cancer.

Conclusions: Occupational and residential exposure to coal operations are associated with worse cancer mortality, underscoring the importance of public health surveillance and research efforts to inform local decision-making on initiating and/or expanding coal operations in the US.

Introduction In January 2025, the US declared its first national energy emergency, and soon after announced plans to scale up coal production and usage.1,2 As one of the world's largest energy consumers, the prospect of increased coal reliance raises concerns about higher greenhouse gas emissions globally,3 and potential health impacts on local populations working at and/or living near coal mining, processing, burning, and waste management sites. Importantly, the power to expand coal operations in the US rests with the very communities most likely to bear the health consequences of coal expansion because permits for coal operations are granted by US state or county authorities.

Cancer is the second leading cause of death in the US,4 with disproportionately high incidence and mortality rates in regions poised for expanding coal activities.5 The simultaneous rollback of environmental protections and incentives for coal expansion risks amplifying exposure to carcinogens and other pollutants in surrounding communities.6 While the carcinogenicity of single pollutants released by coal operations, including cadmium and chromium released during coal combustion and concentrated in coal waste,7,8 and some coal-related occupational activities,9,10 is well-established, people living or working near coal operations are exposed to complex mixtures of pollutants, which may have compounding detrimental health consequences throughout the cancer control continuum. Increased exposure to pollutants can also cause economic burden on communities resulting from premature mortality, increased healthcare costs, and degradation of natural resources that support local livelihoods and wellbeing.11

Two previous reviews examined research on the association between exposure to coal mining and cancer incidence and mortality. One only examined occupational exposures,12 and the other, which encompassed both occupational and residential exposures, did not include studies published after 2012.13 Moreover, neither examined exposures throughout coal's life cycle (e.g., mining, processing, burning, waste management) or outcomes across the cancer control continuum (e.g., prevention, diagnosis, treatment, survivorship, end-of-life care). This systematic review aims to characterize the associations between any type of exposure to any coal operation and any cancer outcome in the US. Such an assessment is urgently needed to inform local decision-making regarding expansion of coal operations.

Section snippets

Search strategy and selection criteria In this systematic review, conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (Supplemental Table 1), studies were identified using “Cancer” or “Neoplasm” and “Coal” as the search terms in PubMed (full search strategy was ("Neoplasms"[Mesh] OR cancer∗ OR carcinoma∗ OR malignan∗ OR neoplasm∗) AND ("Coal"[Mesh] OR "Coal Mining"[Mesh] OR coal OR “coal mining" OR "coal-fired" OR "coal combustion")), Embase, CINAHL, and Scopus . . .

Results Of the 3065 unique articles identified, 159 were further evaluated following abstract review, 33 of which met the inclusion criteria. Twelve additional studies were identified from articles’ reference lists, with a total of 45 included studies (Fig. 1). Most studies (53∙3%) were published after 2012 (Table 1). All studies were observational with cross-sectional (55∙6%), case-control (26∙7%), or cohort (17∙8%) designs. Only two types of exposure to coal operations were evaluated, occupational . . . .

Discussion This systematic review of 45 studies provided insights into the associations between exposure to coal operations and cancer outcomes in communities likely to be impacted by federal government directives to expand coal activities in the US in 2025. Despite great heterogeneity in methodological approaches, which precluded quantitative synthesis of study results, most studies found statistically significant associations between residential and occupational exposure to coal operations and cancer . . .

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Health Harms and Cancers Across the Coal Lifecycle: An Evidence-Based Assessment Claude AI - May 2026

TL;DR

• Coal causes well-documented, large-scale harm at every stage of its lifecycle — from miners (resurgent black lung, lung cancer, silicosis) to communities near power plants (hundreds of thousands of deaths from PM2.5, mercury, SO₂, NOₓ, and heavy metals) to households burning coal indoors (a Group 1 carcinogen tied to extreme lung-cancer rates in Xuanwei, China, plus more than 10 million people affected by coal-burning fluorosis and arsenicosis in Guizhou).
• The International Agency for Research on Cancer (IARC) classifies six coal-related exposures as Group 1 (definite) human carcinogens: indoor emissions from household coal combustion, coal-tar pitches, coal-tars, coal gasification, coke production, and respirable crystalline silica (a major co-exposure for coal miners). Outdoor air pollution and the PM2.5 in outdoor air — both heavily contributed to by coal combustion — are also Group 1.
• Aggressive coal phase-out is the single most consequential public-health intervention available in the energy sector: U.S. coal-PM2.5 alone was associated with 460,000 excess Medicare deaths from 1999–2020 (Henneman et al., Science 2023); EPA's Mercury and Air Toxics Standards (MATS) prevent an estimated 11,000 premature deaths per year; and the 2025 Lancet Countdown attributes ~160,000 averted deaths/year globally to coal reductions since 2010.

Key Findings

1. Coal mining (occupational). Black lung disease (coal workers' pneumoconiosis, CWP) has resurged dramatically in central Appalachia — CDC/NIOSH data show ~20% prevalence among long-tenured Central Appalachian miners (Kentucky, Virginia, West Virginia), the highest rate in 25+ years; ~1 in 20 have progressive massive fibrosis (PMF), and the disease is now appearing in miners under 40 with under 10 years' tenure. The driver is rising silica exposure from cutting thin coal seams through silica-rich sandstone. Per collaborative data compiled by federally supported black lung clinics (Appalachian Voices, May 8, 2026), between 2019 and 2024 about 52% of more than 7,000 miners who received chest X-rays in the clinic network tested positive for black lung. NIOSH (Blackley et al., MMWR 2016; JAMA 2018) documented the largest PMF cluster since the 1970s — 416 cases at three Virginia clinics in 2013–2017. Modern coal miners also have significantly elevated lung-cancer mortality versus the U.S. population (NIOSH, 2023), driven by respirable crystalline silica (IARC Group 1 since 1997), diesel engine exhaust (IARC Group 1; Diesel Exhaust in Miners Study, Silverman et al. 2012 — heavily exposed miners had ~3× lung-cancer risk after smoking adjustment), and radon-222 decay products (Group 1). COPD, chronic bronchitis, and emphysema are markedly elevated independent of pneumoconiosis.

2. Coal combustion / community exposure. Coal-fired power plants emit PM2.5, SO₂, NOₓ, mercury, arsenic, lead, cadmium, chromium, selenium and other toxics. The landmark Henneman et al. (Science, 2023) Medicare study found that coal PM2.5 was associated with 2.1× the mortality risk per μg/m³ of generic PM2.5, and attributed 460,000 U.S. deaths to coal-EGU PM2.5 between 1999–2020, with 10 individual plants each linked to ≥5,000 deaths. EPA estimates the MATS rule (2012, finalized 2024) prevents up to 11,000 premature deaths, 4,700 non-fatal heart attacks, 130,000 asthma attacks, and 540,000 lost workdays annually, with health benefits of $37–90 billion/year (a 3–9× return per compliance dollar). Outdoor air pollution and outdoor PM2.5 are IARC Group 1 carcinogens (lung cancer).

3. Cancers (cross-cutting). IARC Group 1 ("carcinogenic to humans") classifications directly relevant to the coal lifecycle include: indoor emissions from household combustion of coal (lung cancer); coal-tar pitches (skin, lung, bladder); coal-tars (skin, lung); coal gasification (lung); coke production (lung; suggestive evidence for kidney/prostate); soots (skin/scrotal/lung); crystalline silica (lung); diesel engine exhaust (lung; limited bladder); radon-222 and its decay products (lung); arsenic and inorganic arsenic compounds (skin, lung, bladder, also liver/kidney); cadmium (lung); chromium VI (lung); and outdoor air pollution / outdoor PM2.5 (lung). The Xuanwei smoky-coal studies provide some of the strongest dose–response data in environmental epidemiology: smoky bituminous coal was associated with hazard ratios for lung-cancer death of 36 (men) and 99 (women) versus smokeless anthracite (Barone-Adesi et al., BMJ 2012); absolute lifetime lung-cancer death risk before age 70 was ~18–20% in smoky-coal users vs. <0.5% in smokeless-coal users.

4. Coal coking / coke ovens. Coke production is IARC Group 1. The seminal Allegheny County steelworker cohort (Lloyd, Redmond et al.) found that topside coke-oven workers had up to 16× the lung-cancer relative risk of unexposed steelworkers after ≥15 years on the ovens, with consistent dose–response by duration and intensity (the OSHA basis for the 1977 coke-oven emissions standard). Excess mortality was also observed for kidney, prostate, and all-cancers combined. British cohorts (NSF + British Steel, >6,600 workers) showed smaller but consistent lung-cancer excesses (SMR ~125–127% versus regional rates). Skin/scrotal cancer and bladder cancer have been documented in coal-tar/pitch workers; benzo[a]pyrene exposure is the principal mechanism.

5. Indoor coal burning (household). IARC Group 1 since 2006 (re-affirmed 2010, 2012). The Xuanwei/Fuyuan studies in Yunnan, China remain the strongest evidence base: unvented smoky-coal stoves produced indoor PAH concentrations approaching those on top of coke ovens. A retrospective cohort (Barone-Adesi et al., BMJ 2012; n = 37,272) reported absolute risks of lung-cancer death before age 70 of ~18% in men and ~20% in women using smoky coal; switching to portable stoves with chimneys produced large risk reductions. The pooled International Lung Cancer Consortium analysis (Hosgood et al.) confirmed elevated lung-cancer risk for indoor coal use across multiple countries. Beyond cancer, indoor coal contributes substantially to COPD, childhood acute lower-respiratory infections, low birth weight, and cardiovascular disease. The Global Burden of Disease 2021 estimated household air pollution from solid fuels caused ~3.25 million deaths in 2021; WHO has estimated ~420,000 premature deaths/year in China alone from household solid-fuel air pollution.

6. Coal ash / combustion residuals (CCR). Coal ash contains arsenic, lead, mercury, cadmium, chromium, selenium, boron, lithium, molybdenum, thallium, and radium/uranium. EPA's draft 2023 risk assessment found unacceptable cancer and non-cancer risks from coal-ash fill, with arsenic driving cancer risk (EPA finalized a 21-fold increase in inorganic arsenic cancer potency in January 2025). The "Poisonous Coverup" report (2022) by the Environmental Integrity Project (EIP) and Earthjustice, based on self-reported industry monitoring at 292 coal plants in 43 states, found that the coal-ash dumps at 91% of U.S. coal-fired power plants contaminate groundwater above federal safe drinking-water standards, with 96% of those plants proposing no groundwater treatment. EPA has estimated that residents on private wells next to unlined wet ash impoundments could face up to a 1-in-50 lifetime cancer risk from arsenic.

7. Mercury and neurotoxicity. Coal combustion is the second-largest anthropogenic source of mercury globally (~21% of ~2,220 metric tons/year), behind artisanal/small-scale gold mining (UNEP Global Mercury Assessment 2018). It was the largest U.S. anthropogenic source (~50%) before MATS. Once deposited, inorganic Hg is methylated by aquatic microbes into methylmercury, which bioaccumulates in fish. Prenatal methylmercury exposure produces dose-dependent IQ loss: Axelrad et al. (EHP 2007) estimated ~0.18 IQ-point loss per ppm increase in maternal hair mercury, derived from the Faroes, Seychelles and New Zealand cohorts. After MATS, U.S. power-plant mercury emissions fell ~86% by 2017; per EPA's peer-reviewed analysis of CDC NHANES data ("Trends in Blood Mercury Concentrations and Fish Consumption among U.S. Women of Childbearing Age, NHANES 1999–2010," 2013), mean blood methylmercury in women of childbearing age fell 34% from the 1999–2000 cycle to the 2001–2010 cycles, and the percentage above EPA's level of concern fell 65%.

Details

1. Occupational disease in coal miners

Coal workers' pneumoconiosis (CWP) and PMF. After the 1969 Coal Mine Health and Safety Act drove CWP prevalence to historic lows in the 1990s — and nearly eradicated PMF — surveillance through the NIOSH Coal Workers' Health Surveillance Program (CWHSP) detected a sustained resurgence starting around 2000, concentrated in Kentucky, Virginia, and West Virginia. Blackley et al. (MMWR 2016) reported a PMF cluster in eastern Kentucky exceeding any since modern dust laws; a 2018 follow-up (JAMA) identified 416 PMF cases at three Virginia clinics — the largest cluster of its kind in NIOSH history. By 2014–2018, the 5-year moving-average PMF prevalence among Central Appalachian miners with ≥25 years' underground tenure had returned to pre-1969 levels. The CDC currently estimates ~20% prevalence of CWP among Central Appalachian miners; ~5% have PMF. Critically, the disease is appearing in miners under 40 with <10 years' tenure and progressing more rapidly than in earlier generations — features consistent with substantially higher exposure to crystalline silica from cutting through sandstone to reach thin coal seams. MSHA's 2024 silica rule (upheld in court) sets a new respirable crystalline silica permissible exposure limit of 50 μg/m³ (8-hr TWA) with continuous personal dust monitors; effective implementation remains a key uncertainty given recent federal staff cuts at NIOSH.

COPD and chronic bronchitis. Coal mine dust lung disease (CMDLD) is a continuum that includes CWP, silicosis, mixed-dust pneumoconiosis, dust-related COPD, chronic bronchitis, and emphysema. Airflow obstruction is present in roughly 8% of never-smoking miners without radiographic pneumoconiosis, rising to 16% with CWP and 32% with PMF (Laney et al.).

Lung cancer in miners. A NIOSH 2023 analysis across four birth cohorts found U.S. coal miners had significantly elevated lung-cancer mortality compared to the general population. Principal carcinogens are:

• Respirable crystalline silica (IARC Group 1, 1997; reaffirmed 2012). Steenland et al.'s pooled analysis of 10 cohorts (65,980 workers; 1,072 lung-cancer deaths) found excess lifetime lung-cancer risk of 1.1–1.7% at the 0.1 mg/m³ exposure limit then permitted in many countries — above a 3–6% background.
• Diesel engine exhaust (IARC Group 1, 2012). The NCI/NIOSH Diesel Exhaust in Miners Study (Silverman et al., JNCI 2012; DEMS II 2023) found heavily exposed miners had ~3× lung-cancer mortality after smoking adjustment; non-smokers in the highest exposure quartile had 7× the risk of unexposed non-smokers.
• Radon-222 and its decay products (IARC Group 1). Underground mines historically produced high radon exposures; uranium- and hard-rock miner cohorts underpin the BEIR VI risk model.
• Additional exposures include PAHs and, occasionally, arsenic and asbestos.

2. Coal power plants and community/population exposure

Particulate matter and mortality. Henneman et al. (Science 2023) used dispersion-plus-chemical-transport modeling and 650 million person-years of Medicare records to attribute 460,000 excess U.S. deaths to coal-PM2.5 between 1999 and 2020. Per 1 μg/m³ increase in coal PM2.5, all-cause mortality rose 1.12% — 2.1× the risk per unit mass of average PM2.5. Coal-PM2.5 accounted for 25% of Medicare PM2.5 deaths pre-2009 but only 7% post-2012 as plants closed and SO₂ scrubbers were installed. By 2020, annual coal-PM2.5 deaths had fallen to ~1,600, vs. >43,000/year at peak.

SO₂, NOₓ and cardiopulmonary outcomes. SO₂ from coal forms secondary sulfate PM2.5 and triggers asthma exacerbations directly. Casey et al. (Nature Energy 2020) used Louisville's 2013–2016 coal-plant retirement and scrubber installation as a natural experiment: ZIP-code asthma hospitalizations, ER visits, and rescue-inhaler use fell measurably. Yu et al. (American Journal of Respiratory and Critical Care Medicine, 2025), led by Wuyue Yu, PhD (NYU Grossman School of Medicine) with the University of Pittsburgh and the Allegheny County Health Department, studied the January 2016 closure of the Shenango Coke Works in Avalon, PA; pediatric asthma ER visits dropped 41.2% in the three years after closure compared with the three years before, and overall respiratory visits fell 20.5%. NIEHS-affiliated work has linked NOₓ exposure to hemorrhagic stroke in postmenopausal women.

Neurodevelopment and birth outcomes. Maternal residence within 32–48 km of New Jersey coal plants was associated with increased low birth weight (Yang et al.); PM2.5 has been linked to preterm birth, low birth weight, and impaired neurocognitive development.

Global burden. The Lancet Countdown 2024–2025 reports estimate that the global shift away from coal averted ~160,000 premature PM2.5 deaths/year between 2010 and 2022. Vohra et al. (Environmental Research 195:110754, 2021), led by Karn Vohra (Birmingham/Harvard/UCL), estimated 10.2 million global excess deaths in 2012 and 8.7 million in 2018 attributable to outdoor PM2.5 from fossil-fuel combustion — roughly twice the GBD estimate — with the largest national burdens in China (3.9 million in 2012) and India (2.5 million), where coal combustion dominates. The methodological choice of the Vodonos et al. (2018) concentration-response function explains most of the divergence from GBD and is debated.

3. IARC classifications relevant to coal — summary

Group 1 (carcinogenic to humans) with target sites for which there is sufficient human evidence:

• Indoor emissions from household combustion of coal → lung cancer (IARC Monograph 95; Vol. 100E, 2012).
• Coal gasification → lung cancer.
• Coke production → lung cancer (suggestive: kidney, prostate).
• Coal-tar pitches → lung, skin (non-melanoma); limited evidence for bladder.
• Coal-tars → skin (non-melanoma); lung evidence.
• Soots (chimney sweeps; PAH-laden) → skin, lung.
• Crystalline silica (quartz, cristobalite) → lung.
• Diesel engine exhaust → lung (limited: bladder).
• Radon-222 and its decay products → lung.
• Arsenic and inorganic arsenic compounds → lung, skin, bladder (also liver, kidney).
• Cadmium and cadmium compounds → lung.
• Chromium (VI) compounds → lung.
• Outdoor air pollution / particulate matter in outdoor air → lung.
• Aluminum production and iron/steel founding (with coal-tar-pitch and coke-oven exposures) — various cancer sites.

Group 2A/2B (probable/possible): indoor biomass combustion (2A); certain individual PAHs (varied).

4. Coke ovens and coal-tar workers

OSHA's 1977 coke-oven emissions standard (permissible exposure limit 150 μg/m³ benzene-soluble fraction of total particulate matter) was justified by Redmond, Lloyd and colleagues' Allegheny County steelworker cohort, which documented up to 16-fold excess relative lung-cancer risk in topside oven workers with ≥15 years of exposure and dose–response by duration and oven location. Excess mortality was also seen for kidney, prostate, and all-cancers combined. British coke-plant cohorts (n > 6,600; Hurley et al.; updated by Miller et al. 2013) saw a ~25% lung-cancer excess versus the general population (smaller versus social-class-IV referents) with associations to cumulative benzo[a]pyrene exposure. Coal-tar pitch workers have shown excess scrotal cancer (a 1946 UK study found patent-fuel workers had roughly 500× the scrotal cancer mortality), bladder cancer, and renal-pelvis cancer; therapeutic coal-tar preparations (psoriasis ointments) carry documented skin-cancer case-report literature.

5. Household coal: cancer and the Xuanwei studies

Xuanwei County (Yunnan, China) has among the highest female lung-cancer rates in the world, occurring predominantly in never-smokers. The local "smoky" bituminous coal — burned in unvented indoor fire pits to heat homes and cook — produces PAH-laden smoke at concentrations comparable to those measured atop coke ovens, with women non-smokers inhaling ten times the PAH dose of a 20-cigarette-per-day smoker. The 27,310-person smoky-coal cohort vs. 9,962-person smokeless-coal cohort (Barone-Adesi et al., BMJ 2012) yielded:

• Lung-cancer hazard ratio 36 (95% CI 20–65) in men, 99 (37–266) in women for smoky vs. smokeless coal.
• Absolute risk of lung-cancer death before age 70: ~18% (men) and ~20% (women) on smoky coal vs. <0.5% on smokeless coal.
• Lung cancer accounted for ~40% of all deaths before age 60 in smoky-coal users.
• Switching to vented (chimney) stoves substantially reduced risk.

Case-control work (Hosgood, Lan et al.) has further shown that risk varies markedly by geologic coal deposit (ORs 7.5–33.4 across deposits), with the most carcinogenic deposits in Laibin township identified through PAH profiling. 5-Methylchrysene is a particularly potent PAH implicated.

In rural China more broadly, WHO estimated ~420,000 premature deaths/year from household solid-fuel pollution (Smith et al.; WHO Global Burden of Disease). The GBD 2021 estimate for global household-air-pollution mortality is ~3.25 million deaths/year (The Lancet, 2024); coal is one of four solid-fuel categories (with wood, dung, crop residue).

Coal-related arsenicosis and fluorosis in Guizhou. Liu et al. (Environmental Health Perspectives 110(2):119–122, 2002) documented chronic arsenic poisoning from indoor burning of high-arsenic coal (used to dry chili peppers and corn) in southwest Guizhou: at least 3,000 confirmed arsenicosis patients and ~200,000 people at risk; skin lesions including keratoses, hyperpigmentation, ulcers, and skin cancer; hepatomegaly in 20% of cases; cirrhosis, ascites, and liver cancer. Finkelman et al. (PNAS 96(7):3427–3431, 1999) reported coal with up to 35,000 ppm arsenic and dried chili peppers averaging 500 ppm; documented outcomes include Bowen's disease (precancerous keratoses) and squamous cell carcinoma. Coal-burning fluorosis from indoor combustion of fluorine-rich coal — used to dry corn on briquettes binders of high-fluorine clay — affects >10 million people in Guizhou and adjacent provinces (Finkelman et al., 1999); a more recent national assessment (Tu et al., Ecotoxicology and Environmental Safety, 2023) reports ~20 million coal-burning dental fluorosis cases nationally, with >60% in western Guizhou. Skeletal fluorosis can be crippling.

6. Coal ash / coal combustion residuals (CCR)

The U.S. produced ~64 million tons of coal combustion residuals in 2024. Constituents of concern include arsenic, lead, mercury, cadmium, hexavalent chromium, selenium, boron, lithium, molybdenum, thallium, and natural radionuclides (radium, uranium, radon progeny). EPA's draft and final coal-ash risk assessments (2023–2024) identified arsenic ingestion (cancers of skin, liver, bladder, and lung; cardiovascular effects), lithium (renal, thyroid, neurologic), molybdenum (gout-like), and thallium (neurologic) as the main groundwater-driven risk drivers; the January 2025 IRIS reassessment raised inorganic arsenic cancer potency 21-fold. The "Poisonous Coverup" report (Environmental Integrity Project and Earthjustice, 2022), based on self-reported industry monitoring at 292 coal plants in 43 states, found that the coal-ash dumps at 91% of U.S. coal-fired power plants contaminate groundwater above federal safe drinking-water standards, with 96% of those plants proposing no groundwater treatment. EPA has estimated that residents drinking groundwater downgradient of unlined wet ash ponds could face up to a 1-in-50 lifetime cancer risk from arsenic — five orders of magnitude above the 1-in-1,000,000 benchmark normally used in environmental risk management.

Worker-exposure case study — Kingston, TN, 2008. The 5.4-million-cubic-yard TVA spill remains the largest industrial spill in U.S. history. Cleanup workers were told the ash was safe; respirators and Tyvek suits were prohibited. By 2018, more than 36 cleanup workers had died and >200 were sick — ultimately >50 deaths and 400+ ill — from brain cancer, lung cancer, leukemia, lymphoma, blood disorders, respiratory and cardiac disease. A federal jury (2018) found contractor Jacobs Engineering liable; a settlement was reached in 2023. Independent testing showed Kingston ash six- to eight-times more radioactive than surrounding soil, with 26 hazardous heavy metals/toxins.

7. Mercury and neurotoxicity

• Source dominance. Globally, coal combustion is the second-largest anthropogenic mercury source (~21% of ~2,220 metric tons/year), after artisanal/small-scale gold mining (~38%) (UNEP Global Mercury Assessment 2018). In the U.S., coal-fired power plants were responsible for ~50% of anthropogenic mercury emissions before MATS (and remain the single largest source).

• Methylation and bioaccumulation. Inorganic Hg deposited from the atmosphere is converted by aquatic anaerobic microbes to methylmercury (MeHg), which bioaccumulates in piscivorous fish. Nearly every U.S. state has fish-consumption advisories driven primarily by mercury.

• Neurodevelopmental effects. Prenatal MeHg crosses the placenta and the blood–brain barrier and impairs developing neurons. The Faroe Islands and New Zealand cohorts establish dose-dependent deficits in language, attention, memory, and motor performance; the Seychelles cohort is more equivocal (likely reflecting the offsetting benefits of high omega-3 intake). Axelrad et al. (Environmental Health Perspectives 2007) quantified ~0.18 IQ-point loss per ppm increase in maternal hair Hg. Population-level IQ shifts comparable to lead's effect drive measurable disease burdens; among Amazon subsistence fishers, MeHg-attributable mild intellectual disability incidence reaches ~17.4/1,000 infants (Sheehan et al., Bulletin of the WHO, 2014).

• Other effects. MeHg has documented cardiovascular effects in adults (carotid intima-media thickness, hypertension); occupational elemental Hg exposure causes tremor and cognitive effects, though this is not the dominant coal-related pathway.

• MATS impact. Mercury emissions from U.S. coal plants fell ~86% (2010 → 2017) to ~4 tons. Per EPA's peer-reviewed report "Trends in Blood Mercury Concentrations and Fish Consumption among U.S. Women of Childbearing Age, NHANES (1999–2010)" (2013), mean blood methylmercury concentrations in women of childbearing age fell 34% from the 1999–2000 cycle to the 2001–2010 cycles, and the percentage above EPA's level of concern fell 65%. EPA estimates MATS prevents 11,000 deaths, 4,700 heart attacks, and 130,000 asthma attacks per year, with $3–9 in benefits per $1 of compliance cost. Status note: As of February 2026, the Trump EPA repealed the 2024 strengthened MATS rule, a reversal that is being legally challenged and that public-health analysts project will increase Hg, PM2.5, and air-toxics exposure.

Recommendations

These are decision-oriented; specific thresholds that would change them are flagged.

1. For policymakers regulating power plants:

   • Defend and reinstate the 2024 MATS update and the 2024 Legacy Coal Ash Rule. The Henneman et al. and Casey et al. natural-experiment evidence is now strong enough that retiring or scrubbing a coal unit produces measurable mortality, asthma, and birth-outcome benefits within months. Threshold that would change this: a demonstrated alternative regulatory pathway producing equivalent measured PM2.5 and Hg reductions.
   • Accelerate coal retirement on a timeline that matches public-health urgency; Lancet Countdown indicates ~160,000 lives/year are already being saved globally from the existing pace.

2. For mining regulators (MSHA/NIOSH):

   • Fully implement and enforce the 2024 respirable crystalline silica rule (50 μg/m³ PEL; continuous personal dust monitors). Restore NIOSH black-lung surveillance staffing and the mobile X-ray van.
   • Mandate or strongly incentivize participation in screening (currently fewer than one-third of miners participate) so that PMF can be detected early.
   • Threshold: if PMF prevalence in Central Appalachian miners with ≥25 years' tenure does not fall by 25% within five years of full enforcement, additional engineering controls (wet-cutting requirements, mandated dust-suppression equipment, restrictions on cutting silica-rich sandstone) should be required.

3. For occupational health in coke-oven and coal-tar industries:

   • Maintain medical surveillance (lung, skin, bladder, kidney cancers) of currently and formerly exposed workers; risk persists decades after exposure cessation.

4. For coal-ash management:

   • Close and excavate unlined wet impoundments; line and cap dry landfills; ban use of coal ash as residential structural fill. Require groundwater monitoring at the >700 inactive sites newly covered by the 2024 Legacy CCR rule.
   • Make worker PPE (respirators, Tyvek) standard for any ash cleanup; the Kingston litigation establishes both the harm and the standard of care.

5. For households still burning coal indoors:

   • Subsidize switching to LPG, electric induction, or biogas (or at minimum to chimneyed stoves) in the affected provinces of China and in other coal-using regions; the Xuanwei stove-intervention cohorts show large lung-cancer reductions within 5–10 years. In Guizhou, prioritize replacing high-arsenic and high-fluorine local coal sources for indoor use.

6. For clinicians:

   • Take a coal-exposure history (mining, coke ovens, power-plant proximity, indoor coal use in country of origin, coal-ash community exposure) on lung-cancer, bladder-cancer, and unexplained-fibrosis workups.
   • Screen miners and former miners with low-dose CT per current guidelines; the lung-cancer signal is now well-established and miners are eligible regardless of pack-year history if other risk factors are present.

Caveats

• Causal attribution at the population level relies on modeling. Headline figures like "460,000 U.S. deaths from coal PM2.5" (Henneman) and "8.7 million global deaths from fossil-fuel PM2.5" (Vohra) are products of statistical models combining emissions inventories, atmospheric chemistry/transport models, and concentration-response functions. The Vohra estimate is roughly double the GBD because of the Vodonos CRF; experts continue to debate the appropriate dose–response shape at low exposures.

• Smoking confounding. Many coal-miner and coke-oven cohorts had high smoking prevalence, complicating lung-cancer attribution. Best studies (Steenland silica pool; DEMS) explicitly adjust; effects survive.

• Radon vs. diesel co-exposure in miner cohorts complicates attribution; some analysts argue EPA's residential-radon risk estimates may be inflated because original miner cohorts had unmeasured diesel exhaust (Lipsett et al., PLOS One 2017).
• Indoor coal vs. biomass. The IARC Group 1 designation is specific to indoor coal combustion. Indoor biomass (wood, dung, crop residue) is Group 2A — strong evidence but slightly less definitive — though the GBD burden is larger because more people use biomass than coal indoors.
• Mountaintop-removal community studies (Hendryx and colleagues) consistently find elevated cancer, cardiopulmonary, and birth-defect rates in MTR counties versus non-mining or underground-mining counties, but most rely on ecological/cross-sectional designs and have been critiqued for unmeasured confounding (poverty, smoking, healthcare access). A systematic review (Boyles et al., Environmental Research 2017) judged most studies to have moderate-to-high risk of bias while still concluding the pattern of evidence is consistent with harm.
• Some coke-oven cohort evidence is weaker than the regulatory record implies. The British cohort's lung-cancer excess shrinks substantially when compared to social-class-IV referents; the U.S. Allegheny County evidence remains the strongest.
• Political/regulatory volatility. As of mid-2026, several U.S. protections (MATS update, Legacy Coal Ash Rule, NIOSH staffing) are subject to ongoing rollback and litigation. This affects both ongoing exposures and the surveillance infrastructure that would detect them.