Worker Health Study Summaries – Synthetic Dye Manufacturers

Research on long-term exposure

Synthetic Dye Manufacturers (beta-naphthylamine (BNA))


Study Background

NIOSH studied Beta-napthylamine (BNA) exposure among synthetic dye manufacturers.

Previously NIOSH had conducted a study on workers employed at a plant manufacturing synthetic dyes. The study showed an increased risk for cancers of the bladder and esophagus.

Workers were possibly exposed to beta-naphthylamine (BNA) which had been used in the manufacture of the synthetic dyes. BNA has been known to cause bladder cancer.

Why NIOSH Did the New Study

Earlier studies have suggested that working with BNA may cause bladder cancer.

NIOSH wanted to confirm the results of excess cancers of the bladder and esophagus found in the earlier NIOSH study completed in 1985 at the same plant.

Only the main causes of death were examined by the earlier NIOSH study. NIOSH wanted to examine all causes of death as listed on the death certificates in the updated study.

How NIOSH Did the New Study

NIOSH examined the deaths of hourly employees who had worked sometime between 1940 and 1972 at a plant manufacturing dyes.

The updated study looked at all causes of death listed on the death certificates. (The earlier NIOSH study only looked at main causes of death listed on death certificates).

The updated study looked at deaths occurring between 1940-1992. This added 13 additional years to the study. (The earlier NIOSH study only looked at deaths occurring between 1940-1979).

The updated study looked at how much time employees had worked at the plant.

The updated study compared the number of deaths from bladder cancer (as well as other causes of death) to that of the general population of the U.S.

Summary of What NIOSH Found:

Workers had a significant risk of bladder cancer, especially workers employed 10 years or longer.

Workers had a significant risk of diseases of the genitals and urinary organs.

Workers had an increased risk of cancer of the esophagus, but the risk was not as great as seen in the earlier study.

Deaths from lung cancer, prostate cancer and several non-cancer causes including mental diseases, heart diseases, cerebrovascular disease, lung disease, and cirrhosis of the liver were increased

More information

Call NIOSH between 8:00 a.m. and 4:00 p.m. Eastern time toll-free at:

Or write to:
National Institute for Occupational
Safety and Health
4676 Columbia Parkway
Cincinnati, OH 45226

For more information about cancer call:

National Cancer Institute

American Cancer Society
National Office)

To request the study report or other information about occupational safety and health, contact NIOSH at:

NIOSH – Publications Dissemination
4676 Columbia Parkway
Cincinnati, Oh 45226-1998
Telephone Number: 800-356-4676
Fax: 513-533-8573

Bladder Cancer

What You Need to Know About Bladder Cancerexternal icon
NIH Publication Number 01-1559
The National Cancer Institute (NCI) has written this booklet to help patients with bladder cancer and their families and friends better understand this disease. We hope others will read it as well to learn more about bladder cancer.

Steps to Protect Your Health

There are steps you can take right now that will help prevent disease from bladder cancer.

There are specific medical tests on the screening for bladder cancer. Ask your doctor’s advice about taking these tests.

Smoking is a major cause of disease, especially lung cancer and heart disease. If you smoke, you should stop. Even if you have smoked for a long time, stopping now will improve your health.

Drinking alcoholic beverages can increase your risk of cirrhosis of the liver and mental diseases. If you drink alcoholic beverages, discuss with your doctor whether you should reduce your amount or quit.

Eating a variety of fresh fruits and vegetables every day may help prevent cancer.

Exercising (walking, swimming, running, etc.) has been shown to reduce one’s risk of heart disease.

Information on Tobacco Use

The American Cancer Society has pamphlets on stopping tobacco use and classes on quitting smoking. Call their toll-free number, 800-227-2345, which will connect you with an ACS office in your state.

The American Lung Association also has pamphlets and classes on quitting smoking. Call their toll-free number, 800-232-5864, which will connect you with an ALA office in your state.

Information on Heart Disease

The American Heart Association has pamphlets on controlling one’s risk.

factors for heart disease. Call 800-AHA-USAl (800-242-8721) for the nearest office in your state.

Information on Alcohol Use

Alcoholics Anonymous has pamphlets and classes on controlling one’s drinking. Call 212-870-3400 for the nearest office in your city.


Axtell C, Ward E, McCabe G et al. (1998). Underlying and Multiple Cause of Mortality in a Cohort of Workers Exposed to Aromatic Amines. American Journal of Industrial Medicine 34:506-511.

Stern F, Murthy L, Beaumont J et al. (1985). Notification and Risk Assessment for Bladder Cancer of a Cohort Exposed to Aromatic Amines. Journal of Occupational Medicine 27 (7):495-500.

Page last reviewed: April 8, 2020