Scientists have linked many chemicals to an increased risk of developing lymphoma. Although these types of substances aren’t the only cause of lymphoma, limiting people’s exposure to them may help decrease the number of new cases.

One type of lymphoma, non-Hodgkin lymphoma (NHL), is among the most common types of cancer in the United States. NHL accounts for about 4 percent of all newly diagnosed cancers, according to the American Cancer Society, and an estimated 80,000 people will be diagnosed with NHL in 2023.

Continue reading to learn more about the health effects of several kinds of chemicals that may raise the risk of lymphoma.

What Causes Lymphoma?

Cancer can develop if genetic mutations (changes in your DNA) cause cells to grow and divide out of control. If the mutation occurs in white blood cells called lymphocytes, you may develop a type of cancer called lymphoma.

DNA mutations happen frequently and can be caused by errors in cell division, passed down from parents, or result from exposure to harmful substances in your environment. Usually, one mutation isn’t enough to cause lymphoma. It normally takes multiple mutations to cause the lymphocytes to grow out of control.

Since genetic mutations cause lymphoma, risk factors for this cancer include anything that can encourage these changes, including exposure to certain chemicals. Substances that increase your risk of cancer are known as carcinogens.

It's important to note that although science is good at finding correlations (apparent relationships) between factors and disease, correlation doesn’t prove that the factor causes the disease. Researchers have identified many risk factors for lymphoma and are studying their role in the development of the disease. It's also important to note that risk factors vary by the type of cancer or lymphoma.

The following list includes six types of chemicals for which science has found a correlation between exposure and developing lymphoma.

1. Paint Thinners and Other Solvents

Paint thinners use chemicals called solvents to dissolve paint and other substances. Some of these chemicals are toxic and can harm you if you’re exposed. Carcinogenic solvents include:

• Benzene
• Trichloroethylene
• Carbon tetrachloride

Solvents are used in several industries to make all kinds of products, including:

• Paint
• Glue
• Plastics
• Cleaning agents
• Agricultural products
• Pharmaceuticals

Exposure to these chemicals as part of one’s job is called occupational exposure. You may be exposed to solvents if you work in a facility where they’re made or have a job that uses these products.

People who may have higher exposure levels to solvents include:

• Painters
• Printers
• Construction workers
• Agricultural workers
• Funeral directors and embalmers
• Dry cleaners

Several population-based studies have found a link between carbon tetrachloride, trichloroethylene, and benzene exposure and an increased risk of NHL.

A 2009 population-based case-control study of women in Connecticut found that participants with occupational exposure to organic solvents (such as benzene) and chlorinated solvents (such as carbon tetrachloride) had an increased risk of developing NHL compared to those without exposure. The study appeared in the American Journal of Epidemiology.

A 2007 study in Germany found that people exposed to chlorinated hydrocarbons such as trichloroethylene had about double the risk of developing malignant lymphoma. The results were published in the Journal of Occupational Medicine and Toxicology.

2. Pesticides

Pesticides are chemicals that are used to control pests in agricultural crops, industrial settings, or homes. Insecticides (pesticides that help control insects) are commonly used in agricultural and residential areas. The International Agency for Research on Cancer (IARC) has linked development of NHL with two chemicals — malathion and diazinon — used as field crop insecticides.

You might be exposed to pesticides if you work in pest control. However, pesticides are also a common environmental pollutant. Even some insecticides that have been banned for decades due to their negative health effects can remain in the environment for long periods. A 2021 large population-based study in California found that about 44 percent of people diagnosed with NHL were exposed to pesticides in their homes.

Pesticide exposure may also be correlated with poor outcomes in lymphoma treatment.

3. Herbicides

Herbicides are chemicals used to control the growth of unwanted plants. One of the most well-known herbicides is the weedkiller Roundup.

Roundup uses a chemical called glyphosate to kill unwanted plants in crops and on lawns. In 2015, the World Health Organization (WHO) classified glyphosate as “probably carcinogenic to humans,” and the IARC associated this chemical with the development of NHL.

A 2019 meta-analysis found a 41 percent increased risk of developing NHL in people with occupational exposure to glyphosate. This chemical may be more likely to cause a specific subtype of NHL called diffuse large B-cell lymphoma.

4. Tobacco Smoke

It’s well known that smoking tobacco causes many types of cancer. In fact, smoking cigarettes causes about 20 percent of all cancers, according to the American Cancer Society. Exposure to smoke that’s in the environment from burning tobacco or exhaled by a smoker — known as secondhand smoke — is also associated with many different cancers, including lymphoma.

According to the National Cancer Institute, secondhand smoke has more than 69 carcinogenic chemicals, including several that are linked to an increased risk of lymphoma. These carcinogens include:

• Benzene
• Vinyl chloride
• Arsenic

A 2017 study published in the journal BMC Cancer showed that smoking 15 or more cigarettes a day can increase the risk of developing lymphoma by 42 percent.

5. Hair Dye

Hair dyes use chemicals to change the color of hair. You may be exposed to hair dye if you work in a salon, perhaps as a hairdresser or stylist, or regularly use these products.

Studies show that there may be a link between using hair dye and developing NHL. However, epidemiologic studies on hair dye and lymphoma have mixed results, with some showing a correlation and others finding no link.

People who used hair dye before the 1980s may have a higher risk of NHL compared with those using more recent products. Using a dark-colored dye may carry additional risk. A 2019 study in the journal Medical Principles and Practice found that it takes more than 20 years of exposure to hair dye to raise the risk of developing NHL.

6. Industrial Chemicals

You may come into contact with other cancer-causing chemicals through your job or in the environment. People who live near industrial facilities that use these chemicals may be exposed through the air or water supply.

The National Toxicology Program’s Report on Carcinogens links the the development of blood cancers like leukemia and lymphoma to several chemicals, including:

• Ethylene oxide
• Vinyl chloride
• Benzene
• Formaldehyde

Can You Reduce Your Risk of Lymphoma?

You may not be able to reduce your risk of developing lymphoma. Most people who work closely with the chemicals discussed here don’t develop lymphoma. The cause of lymphoma usually isn’t known.

However, if you have a job that could expose you to carcinogenic chemicals, talk to your employer about ways to limit your exposure, such as using personal protective equipment. You can also check resources from the Occupational Safety and Health Administration (OSHA) on evaluating exposure to carcinogens at work. The Environmental Protection Agency (EPA) evaluates the potential of pesticides and other chemicals to cause cancer.

To reduce your chemical exposure, you can also take precautions like these:

• Ensure you are in a well-ventilated area when working with paint thinners or paint.
• Avoid unnecessary benzene exposure by taking care when filling a vehicle’s gas tank.
• Avoid smoking cigarettes. If you smoke, talk to your doctor about the best way to quit.
• Choose smoke-free restaurants and indoor activities to avoid secondhand smoke.

Talk with your health care provider if you think you have been exposed to chemicals that could increase your risk of lymphoma.

Talk With Others Who Understand

MyLymphomaTeam is the social network for people with lymphoma and their loved ones. More than 15,000 members understand what it’s like to face lymphoma and can provide support and answers.

Do you work in a job where you’re exposed to carcinogenic chemicals? What steps have you taken to reduce your risk? Share your experience or post a comment on your Activities page to start a conversation.