PERSONAL HEALTH : Risky Businesses : Health: Job stress and accidents can explain high death rates for some occupations. Experts say there’s a need to identify the risks that may come with a job.
Roofers are three times more likely than the average person to die of hypertension. Secretaries die of breast cancer at rates one-third higher than other women workers. Male dentists and physicians have suicide rates twice that of men in other jobs.
These are some of the startling, controversial findings from a new state report on health risks related to occupation.
The findings are statistical links--there is no proof, for example, that something about being a secretary causes breast cancer. But occupational safety and health experts say the report illustrates the need to identify possible health risks linked to particular jobs.
No one is saying that will be easy.
“You can, to some degree, determine the elements in the workplace that would be contributing to illness,” said Judy Erickson, an occupational health risk researcher at USC. “But it’s a monster, monster puzzle. Nothing can be studied in isolation.”
In recent years, certain “right-to-know” laws have focused attention on job-related health risks by requiring employers to alert workers to potentially dangerous substances, Beaumont said.
And, with workers’ compensation claims citing job stress on the rise, concern is mounting about working conditions that might contribute to health problems, Erickson said.
Experts generally agree that, after exposure to toxics, job stress will emerge as a leading determinant of overall health. “That seems to be where the evidence is pointing right now,” Erickson said. “Stress claims are going up. California is leading the nation in this.”
Some occupational health risks are obvious. It’s no surprise, for example, that construction workers have a higher rate of accidental falls.
But gauging just how much jobs contribute to illness or death is a tricky business that experts are just beginning to explore, Erickson said.
Dr. S. Leonard Syme, an epidemiologist at the School of Public Health at UC Berkeley, observed: “When you look at jobs and you look at disease outcomes, we can’t explain (the statistical link to) more than half of all the diseases we see.”
The new report confirms that assessment. The California Department of Health Services’ occupational mortality survey is the first ever to try to remove some factors that contribute to illness--such as alcohol consumption, smoking and socioeconomic status--to isolate effects of occupational hazards.
When those lifestyle factors were neutralized statistically, much of the variation in death rates among occupational groups disappeared, researchers found. But there were striking exceptions, raising many more questions than answers.
“We have cast a very broad net here, looking at all different occupations without focusing in on anything in particular. But there were some findings I thought were remarkable,” said James Beaumont, a UC Davis scientist who co-wrote the study. The study, for example, found that accidental deaths among agricultural workers was 60% above the average rate for all occupations.
“The high rate of injury in agricultural occupations was astounding to me,” Beaumont said. “We all thought of agriculture as dangerous, but this quantifies, for California, how much higher the accident rate is.
“The suicide rate among physicians and dentists was also very high. This has been raised before, and this study substantiated it. There is a lot of speculation about the cause, but stress is No. 1.”
Job stress and accidents might explain high death rates for some occupations, Beaumont said. But other unusual findings are harder to explain, such as higher rates of death from hypertension among roofers.
“It is a very different kind of job,” Beaumont said. “There is nothing else quite like it. Some roofers breathe petroleum fumes from tar (which could contribute to hypertension). And the nature of being on a roof might be quite stressful.”
Beaumont said the study’s authors also were stumped by the high death rates from chronic obstructive pulmonary disease in farmers, especially black farmers. The disease is associated with smoking, but the excess in farmers is still evident after the smoking risk factor is removed. “It’s possible the disease is related to their work,” Beaumont said.
The study did not try to explain death-rate variations among races.
Also inexplicable is the high breast cancer death rate among secretaries and typists. Beaumont suggested that the 33% excess in secretaries and typists might even be a statistical fluke. “I’m not sure what to make of it,” he said. “I’m not sure what could be happening there biologically.”
Despite the mysteries, the report is valuable as an indicator of women’s occupational health concerns, said Gwendolyn Doebbert, chief of health demographics for the Department of Health Services.
The report is the second of a series of California Occupational Mortality studies, the first of their kind to include female and black workers. Statistics on Latinos, the first to compare occupational death rates in that population, will be released later this year.
“There is so little known about women’s health and their occupations,” she said. “Why are the death rates high for waitresses and telephone workers? And vocational nurses and health aides had very high rates for a number of causes of death.”
White female vocational nurses and health aides had an overall death rate 72% in excess of what is considered normal, the study showed, while black female cosmetologists had an overall excess death rate of 77%.
The study also could reveal possible problems with occupations not normally considered risky, Doebbert said.
For example, architects have low death rates. But given that smoking and drinking rates among architects are low and their economic status is generally high, the California study revealed that the group has higher-than-normal death rates from ischemic heart disease, circulatory-system problems and digestive organ cancers. The findings suggest that architects might be exposed to some substance that can lead to illness.
“Overall, architects had fairly good health status. But they still had high death rates for some disorders,” Doebbert said. “So a study like this gives some good clues. We need to look at what items suggest a behavior (that contributes to illness) and what is more likely to be related to exposures.”
The report is controversial, because of what is not considered.
One problem is that the study focuses on death rates, Beaumont said. Many health conditions that might be linked to occupation don’t result in death.
“It would be preferable to look at illness,” he said. “There is a lot of illness that does not result in death. For some types of cancer, such as breast cancer, where many people do survive, it would be preferable to look at incidence. It isn’t possible, though. There is no data out there.”
The study also fails to consider genetic factors, and other individual lifestyle factors, USC’s Erickson said. “I think it’s really hard to control some of these variables,” she said. “You can control them statistically, but you are bringing in a lot of things that are hard to define.”
Nevertheless, the research breaks ground that is of interest to both workers and employers, Erickson said.
The California Occupational Mortality reports were ordered by a California Senate resolution in the late 1970s after lawmakers expressed a fear that growing numbers of workers were becoming ill because of exposure to toxic substances. But legislators cited a profound lack of information on the topic.
According to Berkeley’s Syme, studies of individuals in a wide range of occupations shows that good health seems to rest on how much individuals can control their own destiny. People who can control events affecting their lives at work are healthier and more productive, he said.
For example, a study of more than 17,000 male British civil servants found that the highest rates of coronary heart disease were among the lowest socioeconomic class of workers. This relationship was found, despite the workers’ age, smoking habits, cholesterol level and level of physical activity.
Even among the two upper tiers of British society, the second group from the top, consisting of doctors and lawyers, had heart disease rates twice that of the upper-class nobility, said Syme.
“People don’t do well when they are not able to influence the events that affect their lives,” Syme said.
HIGH-RISK OCCUPATIONS
The California Occupational Mortality Survey identified several occupations in which the risk of death was excessive. The study from which this table was derived did not consider the reasons for differences between black and white mortality rates.
Occupation Cause of Death *Pct. Male dentists and Suicide due to 121% doctors (white) job-related stress Male dentists and Suicide due to ** doctors (black) job-related stress Secretaries and Breast cancer 33% typists (white) Secretaries and Breast cancer 74% typists (black) Roofers (white) Hypertension (stress 199% and exposure to chemicals) Roofers (black) Hypertension (stress 203% and exposure to chemicals) Vocational nurses/ Suicide 179% health aides (white) Vocational nurses/ Suicide 145% health aides (black) Plant and systems Lung cancer 177% operators (white) Plant and systems Lung cancer ** operators (black) Farmers (white) Chronic pulmonary disease 65% Farmers (black) Chronic pulmonary disease 337%
* Percentage above normal. ** Insufficient data. Source: Department of Health Services, UC Davis
