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Senators voted to turn off pollution controls. Now it is up to the House.
On May 1, 2025, 52 Senators voted to repeal Clean Air Act protections against seven of the world’s most toxic air pollutants, including dioxins, PCBs, lead, and mercury. Now the resolution heads to the House of Representatives for a vote.
If it passes the House, the resolution would allow 1,800 of the nation’s largest industrial polluters, including chemical manufacturers, pesticide makers, refineries, and other large facilities, to permanently shut off their pollution controls for the most potent carcinogens and toxic chemicals. These air pollutants cause cancers, birth defects, and children’s developmental disorders.
The measure would allow these companies to open the spigot for these most insidious chemicals, and to stop monitoring or reporting their emissions.
These chemicals and their degradation products persist in the environment; contaminate our air, water, and food; and accumulate in our bodies over our lifetimes, stored in our fatty tissue. We pass them along to our babies during fetal development and breastfeeding, harming our children and future generations. They are dangerous even in tiny amounts. While other chemicals are regulated by the tens of tons, it only takes fractions of a gram of these ultra-toxic pollutants to trigger cancers, reproductive pathologies, and other harms.
So let’s make it perfectly clear. If the House joins the Senate in passing this resolution, it will allow industrial polluters to release unlimited quantities of the following chemicals:
1. Mercury
Mercury is an extremely toxic metal that is quickly absorbed in the body through inhalation, ingestion, and skin contact. It is especially insidious when combined with carbon to form methylmercury, which biomagnifies in the food chain, reaching especially high concentrations in fish and shellfish. Mercury can move freely across the placenta and into the human fetus. It can also cross the blood-brain barrier and remain in brain cells for years or decades.
Mercury moves freely across the placenta and into the human fetus. It can also cross the blood-brain barrier and remain in brain cells for years or decades. Mercury is linked to developmental deficits in children, and it also affects the heart, lungs, central nervous system, reproduction, kidneys, and gastrointestinal tract. Researchers are studying possible links to autoimmune effects and to leukemia and other cancers. Mercury is released by coal-fired power plants and industrial boilers, waste incineration facilities, and gold-mining operations.
2. Alkylated lead
Alkylated lead is a combination of the toxic element lead and fossil fuel hydrocarbons. It affects nearly every organ of the body. It can cause reduced cognitive function and other neurotoxic effects in children, as well as cardiovascular, reproductive, gastrointestinal, and urinary system disorders.
During pregnancy, lead crosses the placenta, causing fetal harm. The International Agency for Research on Cancer classifies lead as a known human carcinogen. For more than 60 years, alkylated lead (in the form of tetraethyl lead and tetramethyl lead) was used as an additive in gasoline. It is still used in fuels for aviation, motor sports, and off-road vehicles. Other sources include lead smelting, waste incineration, and lead-acid battery manufacturing.
3. & 4. Dioxins and furans
Dioxins are among the most toxic chemicals known to humankind. They are classified by the International Agency for Research on Cancer as a known human carcinogen. Together with the chemically similar furans, they are listed on Stockholm Convention Annex C, unintentionally produced chemicals that must be minimized and, where feasible, eliminated.
Dioxins and furans persist in the environment for decades. They accumulate in fatty tissue and are linked to altered immune function, increased susceptibility to infections, thyroid and liver function abnormalities, birth defects, child developmental disorders, reproductive problems, diabetes, and cancers.
Dioxins and furans form in high-temperature reactions between organic compounds and chlorine, for example, during waste incineration, metal smelting, wildfires, diesel fuel combustion, and the manufacture of chlorinated pesticides and other petrochemicals.
5. PCBs
PCBs, or polychlorinated biphenyls, were first manufactured commercially a century ago and were soon considered indispensable due to their low flammability, high stability, low electrical conductivity, and high resistance to thermal breakdown and to other chemicals.
They are no longer manufactured intentionally but continue to be released as a by-product air pollutant from fossil fuel combustion, chemical manufacturing, metal smelting, and waste incineration. In addition, they are still found in older equipment, such as transformers, fluorescent lights, building materials, and paints. Some of the highest PCB exposures are at e-waste recycling sites.
The International Agency for Research on Cancer classifies PCBs as carcinogenic to humans, and the Stockholm Convention requires parties to take steps to eliminate their production and use, under Annex A, and their unintentional release, under Annex C. PCB exposures are linked to neurological pathologies, dementia, immune system dysfunctions, cardiovascular diseases, and cancer. They are also associated with reduced fertility and with reproductive harms that can be passed on to future generations.
6. Polycyclic organic matter
Polycyclic organic matter, such as polycyclic aromatic hydrocarbons (PAHs), includes potent carcinogens and mutagens formed during the incomplete combustion of fossil fuels, wood, and other materials.
In the atmosphere, these chemicals bind to particle pollution, including the ultra-fine particles that penetrate deep into the respiratory system, liver, kidneys, heart, and brain. Cancer is the biggest concern, including cancers of the lungs, bladder, and breast. Sources include vehicle exhaust, municipal waste incineration, coke oven emissions, home heating, laying tar, and cigarette smoke.
7. Hexachlorobenzene
Hexachlorobenzene (HCB) is designated a probable human carcinogen and a hormone-mimicking chemical. Exposure during pregnancy, childhood, and adolescence has been linked to elevated risk of breast cancer.
Hexachlorobenzene is also known for its toxicity to the liver, kidneys, and immune and nervous systems. The Stockholm Convention lists hexachlorobenzene on Annexes A and C, given its persistent, bioaccumulative, and toxic properties. It was formerly used in fungicides and continues to be released by industrial sources as a by-product in the production of chlorinated solvents and other chemicals.
Homes next to an oil refinery in Port Arthur, Texas. (LM Otero/AP)
The bottom line
No Congress has ever stripped away protections against toxic air pollution—let alone on this massive scale. It is inconceivable that all those Senators who voted to repeal these protections even understood what they were voting to do.
These toxic exposures are preventable: just keep the pollution controls ON! What politicians are doing is shameful, cruel, and reckless.
We need to protect the health of children and families from the most potent carcinogens
known to humankind. We urge the U.S. House of Representatives to prevent this vile and unprecedented rollback of Clean Air Act protections.
Released: May 2025
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