Emerging Contaminants – Should We Worry?

When the Hempstead Harbor Protection Committee was founded in 1995 to protect the water quality of Hempstead Harbor, the main concerns were bacteria levels and excess nitrogen as these could respectively cause beaches to close and lead to low dissolved oxygen levels that could harm wildlife and cause algae blooms.

While these remain issues of concern, we now have other pollutants to worry about which are referred to as “emerging contaminants”. Of the emerging chemicals, the main focus now is on 1,4-Dioxane and Per- and polyfluoroalkyl substances (collectively known as “PFAS”) as these are being found virtually everywhere. This article will provide a basic overview of these substances.


1,4-Dioxane is an emerging contaminant found in Long Island’s groundwater (which ultimately flows to our waterbodies). It is a synthetic organic compound not found in nature. 1,4-Dioxane is listed as “likely to be carcinogenic to humans,” and has been linked to tumors of the liver, kidneys, and nasal cavity. 

Originally,1,4-dioxane was used as an industrial solvent stabilizer and found widely in paints, primers, varnishes, degreasers, and inks. Although it has been phased out of use in some of these applications, many still contain it. 1,4-Dioxane does not easily degrade or break down in the environment and is highly mobile in soil and groundwater.

Perhaps of greater concern is that 1,4-Dioxane is also found in nearly halfof personal care products, including laundry detergents, dishwashing soaps, shampoos, cosmetics, deodorants, and body lotions, including baby wipes and baby shampoos. It exists in these products, not as an ingredient itself, but as a byproduct of the breakdown of their ingredients. Because of this, you will not see it listed as an ingredient on the labels. To know if a product is likely to contain it, look for the names of ingredients which include 

“-eth” or “-oxynol” in part of their names, such as “sodium laurethsulfate.” 

Some laundry detergents have been found to have the highest levels of 1,4-dioxane of any consumer products, with levels over 50 parts per million, a concentration equivalent to over 100,000 times the EPA’s Cancer Risk Guideline for drinking water. Because of this, laundromats are a potential sources of 1,4-dioxane contamination. 

Currently there is no federal drinking water standard specifically for 1,4-dioxane. On July 8, 2019, Governor Cuomo announced that the NYS Department of Health agreed to adopt the nation’s most stringent drinking water standard for 1,4-Dioxane as well as for PFAS – 10 parts per trillion (US EPA’s guidance level is set at 70 parts per trillion). The Health Department is beginning the regulatory process for adopting these enforceable standards. Also, in February of this year, the NYS DEC issued a memorandum requiring review and/or testing of groundwater at current and past remedial sites for these contaminants. In addition, soil imported to a site for use in a soil cap, soil cover, or as backfill must be sampled for both types of contaminants.

The Suffolk County Water Authority is piloting a new system for the removal of 1,4-dioxane from drinking water. Conventional carbon based filtration systems do not adequately remove 1,4-dioxane. This new pilot system utilizes a process known as advanced oxidation. Smaller trials using advanced oxidation have demonstrated success in removing the chemical.


Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that include PFOA and PFOS, and others. Both chemicals are very persistent in the environment and in the human body – meaning they don’t break down and they can accumulate over time. There is evidence that exposure to PFAS can lead to adverse human health effects. They have been manufactured since the 1940s and 

can be found in food packaging, water-repellent fabrics (such as Gore-Tex), non-stick coatings (such as Teflon), fire-fighting foams, and even food (such as animals and fish that have consumed them).

Certain PFAS chemicals are no longer manufactured in the United States as a result of phase outs including the PFOA Stewardship Program in which eight major chemical manufacturers agreed to eliminate the use of PFOA and PFOA-related chemicals in their products and as emissions from their facilities. Although PFOA and PFOS are no longer manufactured in the United States, they are still produced internationally and can be imported into the United States in consumer goods such as carpet, leather and 

apparel, textiles, paper and packaging, coatings, rubber and plastics.

Certain PFAS can accumulate and stay in the human body for long periods of time. There is evidence that exposure to PFAS can lead to adverse health outcomes in humans. The most-studied PFAS chemicals are PFOA and PFOS. Studies indicate that PFOA and PFOS can cause reproductive and developmental, liver and kidney, and immunological effects in laboratory animals. Both chemicals have caused tumors in animals. The most consistent findings are increased cholesterol levels among exposed populations, with more limited findings related to low infant birth weights, effects on the immune system, cancer (for PFOA), and thyroid hormone disruption (for PFOS). The US EPA has determined that there is “suggestive evidence of carcinogenic potential” for PFOA.

On July 8th, the Governor also announced the that $370 million in grants will fund the planning and development of new local infrastructure projects to combat emerging contaminants (including $30,000 to the Roslyn Water District for 1,4-dioxane treatment planning). In addition, $27 million was awarded to nine Long Island projects to remove emerging contaminants from drinking water (including the nearby Oyster Bay Water District).  While this sounds like a lot, it is only the beginning of a long and expensive process to protect us from these ingredients. Until these contaminants are fully removed from all products, your purchasing decisions as a consumer can certainly help keep our waters clean and your family healthy.

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