A study of 126,000 IBM employees commissioned by the world’s largest computer company found that workplace conditions did not cause cancer or other fatal illnesses, but some diseases warranted further research, IBM said on Wednesday.

IBM commissioned the study in 2000. The company has faced dozens of lawsuits from former employees who alleged that IBM knowingly exposed them, or their unborn babies, to dangerous chemicals.

Critics and activists expressed skepticism about results of the study, which was carried out by researchers from Harvard University and the University of Alabama at Birmingham.

A group of occupational health professionals and environmental activists have been highly critical of International Business Machines Corp.‘s handling of worker health matters. These critics have argued that the computing industry pioneer abandoned its responsibility to protect employees and their children from cancer and birth defects.

Armonk, New York-based IBM shared details of the study’s conclusions in a memo to employees from the company’s top doctor, said company spokesman Chris Andrews. The memo, which was made available to Reuters, did not name which ailments warranted further study.

Further details will be disclosed in science journals, Andrews said.

The researchers said results for some diseases, within some subgroups of employees, warranted further study. The research looked at the health records of 126,000 employees who worked at IBM locations in three states between 1965 and 1999.

The study, which IBM said was commissioned before the lawsuits were filed, also showed that all workers - as well as employees who worked in electronics “clean rooms” where potential exposure to chemicals is highest - had lower mortality and cancer incidence than the general public.

Sheila Davis, director of the clean computer campaign for the Silicon Valley Toxics Coalition, an advocacy group, said it would be premature to make conclusions about the study before greater details were published.

Davis added that she was skeptical of IBM’s findings, noting that some other studies that were not paid for by the computer maker came to other conclusions.

“It’s not a surprise that if IBM sponsors a study they would get the results they’re looking for,” Davis said.

In August, the U.S. Semiconductor Industry Association said it had begun to seek proposals to carry out the first industrywide study of worker health issues. The group came under pressure over the past year amid a high-profile trial against IBM in California by three former workers.

IBM disputes the allegations, and has either prevailed in or settled many of the cases.