Cemetery Pollution: Groundwater, Embalming and Radiation

Author: Ian C. Langtree - View Credentials
Published: 8 Oct 2015 - Updated: 8 Nov 2026
Publication Type: Informative

Table of Contents:
Synopsis - Definition - Overview - FAQs - Insights, Updates - Related Content

Synopsis

This information explains how cemeteries can act as a little-noticed source of soil and groundwater pollution, from formaldehyde-based embalming fluid and wood preservatives, paints and metal fittings on coffins to mercury from dental fillings and chemicals used on cemetery grounds. It draws on a World Health Organization briefing on cemetery siting, the International Agency for Research on Cancer classification of formaldehyde, and a case report in JAMA describing radioactive contamination of a crematorium after a cancer patient who had received a radiopharmaceutical was cremated. The page also describes green and natural burial as a lower-impact choice, which makes it useful for families planning funerals, people living near older cemeteries who rely on wells, and anyone interested in environmental health.

At a Glance

• 1 - Dental amalgam fillings are about half mercury by weight.
• 2 - Embalmers and funeral workers face the most direct exposure to formaldehyde.
• 3 - Formaldehyde breaks down in soil far faster than arsenic, which never breaks down.
• 4 - A crematory operator was found to carry a radioactive tracer he had never received as a patient, likely from cremations.

Topic Definition

Cemetery Groundwater Contamination

Cemetery groundwater contamination is the pollution of soil and underground water by substances released from graves, including decomposition products, embalming chemicals such as formaldehyde, wood preservatives, paints and metals from coffins and caskets, and mercury from dental fillings. The risk is greatest where graves lie close to the water table or near wells, springs and drains.

Overview

Agriculture, industry and landfills are usually thought of as the main human sources of soil and groundwater pollution, but cemeteries can also release contaminants into the ground. Embalming chemicals, coffin materials, metals from medical devices and dental work, and the products of decomposition can all reach nearby soil and water, especially where graves sit close to the water table. Cremation raises its own, much rarer, issue: radioactive medicines given to patients shortly before death.

What Is Groundwater Pollution?

Groundwater is the water held in soil and rock beneath the surface, and it supplies wells and springs used for drinking water in many areas. It becomes polluted when substances such as fuel, road salt, fertilizers or chemicals soak down from the surface. Contamination can also occur naturally, for example when arsenic or other minerals dissolve from the surrounding rock.

Cemeteries and Burial Practices

A cemetery is land set aside for burying the dead, while the older word graveyard originally meant a burial ground beside a church. Modern burial in many countries involves embalming, a sealed wooden or metal casket and often a concrete or steel vault, so a large cemetery can hold many tons of metal, wood, concrete and chemicals. A briefing prepared for the World Health Organization concluded that the main risk from cemeteries is to groundwater, and recommended that graves be sited well above the highest water table and away from springs, watercourses and drains [Ucisik and Rushbrook, 1998].

Coffins and Caskets

Wooden coffins may contain varnishes, sealers, paints and wood preservatives, and metal handles and ornaments are often plated or painted. Preservatives used on wood have included chromated copper arsenate, copper naphthenate, alkaline copper quaternary and copper azole compounds, and older paints often contained lead. Metal caskets and fittings slowly corrode in the ground. As these materials break down over decades, metals such as arsenic, copper, chromium, lead and zinc can enter the surrounding soil.

Formaldehyde and Embalming Fluid

Embalming slows decomposition long enough for a body to be viewed, and formaldehyde is the main ingredient in most embalming fluids. The International Agency for Research on Cancer (IARC) classifies formaldehyde as carcinogenic to humans (Group 1), based mainly on evidence that it causes nasopharyngeal cancer, with evidence also linking it to leukemia [International Agency for Research on Cancer, 2012]; see our list of human carcinogens. The greatest exposure risk is to embalmers and funeral workers who handle it every day. Once buried, formaldehyde breaks down relatively quickly in soil and water, unlike metals such as arsenic, which do not break down at all.

Mercury and Other Contaminants

Dental amalgam fillings, which are about half mercury by weight, and some implanted medical devices can release metals as a body decomposes. Cremation releases mercury from fillings into the air unless crematoriums use filters. Pesticides, fertilizers and weed killers used to keep cemetery grounds green can also run off into soil and water. Most studies find that the amounts reaching groundwater from well-sited and well-managed cemeteries are small, but older or poorly sited cemeteries in wet ground pose a greater risk to nearby wells.

Radiation Contamination After Cremation

Radiopharmaceuticals, radioactive medicines used to diagnose and treat cancer and other diseases, are given to millions of patients each year. If a patient dies soon after treatment, cremation can vaporize the radioactive material. In a case reported by doctors at Mayo Clinic Arizona, a 69-year-old man was treated with lutetium Lu 177 dotatate for a pancreatic neuroendocrine tumor, died two days later and was cremated. About a month after treatment, the crematory oven, vacuum filter and bone crusher were found to be contaminated with lutetium 177, and the crematory operator's urine contained a different radioactive tracer, technetium Tc 99m, which he had never received as a patient [Yu et al., 2019]. The researchers judged the doses involved to be very low, but called for clear rules on handling and notifying crematoriums about patients who die soon after receiving radioactive drugs, since regulations vary from state to state.

Green and Natural Burial

Green burial, also called natural burial, avoids embalming, concrete vaults and metal caskets. The body is buried in a biodegradable coffin, shroud or blanket, often in a natural setting where the land is protected from development. Dr. Billy Campbell, a rural doctor, is reported to have opened the first modern green cemetery in the United States at Ramsey Creek Preserve in South Carolina in 1998. Conservation burial grounds go further, using burial fees to protect and restore natural habitat. In the United States, embalming, sealed caskets and burial vaults are generally not required by law, although individual cemeteries may require a vault, so families who prefer a simpler and lower-impact funeral can ask funeral homes and cemeteries about their options.

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Frequently Asked Questions

Is it safe to drink well water near a cemetery?

Usually yes, but if your well is close to an old or large cemetery, especially in wet ground, consider having the water tested by a certified laboratory.

How long does a body take to decompose in a grave?

It varies widely with soil, moisture, temperature, embalming and the type of casket, from several years to many decades.

Is embalming required by law?

In the United States, embalming is generally not required by law, though rules can apply in special situations such as transporting a body or a delayed burial.

Is cremation better for the environment than burial?

Cremation avoids land use and embalming chemicals but uses fuel and releases emissions, including mercury from dental fillings unless filtered.

What is water cremation?

Water cremation, also called alkaline hydrolysis, uses water, heat and an alkali to break down a body. It is legal in a growing number of U.S. states.

What is a burial vault?

A burial vault is a concrete or metal container placed around a casket to stop the ground from sinking. Many cemeteries require one, but laws generally do not.

Can people with disabilities plan a green burial in advance?

Yes. Anyone can record their wishes in an advance funeral plan or will and discuss them with family, a funeral home or a green burial ground.

Are funeral workers protected from formaldehyde?

In the United States, workplace formaldehyde exposure is regulated by the Occupational Safety and Health Administration, which requires ventilation, monitoring and protective equipment.

References

• International Agency for Research on Cancer. (2012). Chemical agents and related occupations (IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 100F). World Health Organization.
• Ucisik, A. S., and Rushbrook, P. (1998). The impact of cemeteries on the environment and public health: An introductory briefing. World Health Organization Regional Office for Europe.
• Yu, N. Y., Rule, W. G., Sio, T. T., Ashman, J. B., and Nelson, K. L. (2019). Radiation contamination following cremation of a deceased patient treated with a radiopharmaceutical. JAMA, 321(8), 803 - 804.

Insights, Analysis, and Developments

Editorial Note: For most people, the cemetery down the road is not a health threat. Studies suggest that well-sited and well-managed cemeteries release only small amounts of contaminants, and the people most exposed to embalming chemicals are those who work with them every day. The concerns grow with older burial grounds in wet ground, private wells close to graves, and the slow buildup of metals over many decades. Communities planning new cemeteries can follow siting guidance that keeps graves well above the water table and away from springs and drains, and families can reduce their own footprint by choosing simpler options such as natural burial, which skips embalming, concrete vaults and metal caskets.

Author Credentials: Ian C. Langtree is a writer, editor, and the founder and Editor-in-Chief of Disabled World, which he established in 2004 as one of the longest-running independent resources for disability news and information. Over more than two decades, he has written and edited thousands of articles on disability rights, health, accessibility, and assistive technology. Drawing on a global perspective shaped by extensive travel and lived experience, Ian is a committed advocate of the Social Model of Disability, the framework developed by disabled activists in the 1970s that focuses on removing societal barriers rather than on individual impairments. His writing is grounded in that framework and in a lasting commitment to disability rights, accessibility, and social inclusion. To learn more about Ian's background, expertise, and accomplishments, visit his full biography.