Work making you ill?

From the well-published dangers of night shift work to the joy-robbing effects of job stress, the workplace can be really bad for your health. And the dangers often lie in the most unexpected places.

Pilots
There are obvious hazards to spending large amounts of time jetting 35 000 feet above the earth. According to the Accident Statistics website, the survival rate of aircraft accidents is a mere 24%, but then again, the same website also says that you have a 1 in roughly 10 million chance of dying in an airplane.

But there is another, unseen hazard to this job. Because of the long periods they spend at high altitudes, airline pilots' exposure to cosmic radiation may raise their odds of developing genetic abnormalities that could contribute to cancer. A new study, published in the journal Occupational and Environmental Medicine, found that for every 10-year increase in flight experience, the rate of chromosome translocations (a genetic abnormality) increased by 81%. The researchers says that long-range studies are now needed to establish whether this translates into higher cancer risks.

Firefighters
Whereas firefighters tend to be fitter and healthier than the general population, they do face some unique risks.

No, we're not talking about the obvious heat and flames. According to a study published in the New England Journal of Medicine, heart disease causes 45% of deaths among firefighters while on duty.

This risk is particularly high while they're actively fighting fires. According to the researchers, the risk of cardiac death was at least 12 times higher during such emergency duty than during non-emergency duty.

It is thought that stress, pre-existing heart conditions and inhaling environmental pollutants all contribute to the increased risk.

Police face higher heart disease risk
Police officers may have a higher-than-average risk of developing heart disease -- not all of which can be explained by traditional risk factors, a new study suggests.

Researchers found that compared with the general population, officers with the Buffalo, New York, police force showed an elevated rate of early atherosclerosis -- a build-up of fatty deposits in the arteries than can lead to heart disease or stroke.

The findings suggest that aspects of police work itself may take a toll on heart health, the researchers report in the Journal of Occupational and Environmental Medicine.

Exactly what those factors are is not known, but stress is one suspect, Dr John Violanti, who was involved in the study said. Over the course of a career, police officers are exposed to chronic, and sometimes traumatic, stress, noted Violanti, an associate professor of social and preventive medicine at the State University of New York at Buffalo.

Violanti's team found that even when they factored in age, sex and a range of other heart disease risk factors, police officers generally had more thickening in the carotid arteries. For now, the bottom line for police officers is that they should try to rein in all the heart risk factors that they can control -- by, among other things, following a healthy diet, getting regular exercise and not smoking, Violanti said.

Truck drivers
Apart from spending long hours in a sedentary position and being exposed to high levels of exhaust fumes, truck drivers may also face an increased risk of hearing loss, according to a report in the American Industrial Hygiene Journal.

The noise made by a truck is estimated at an average of about 83 decibels (dB), while the maximum safe noise exposure level over an eight-hour period is 85 dB. So as soon as the driver opens a window or turns on the radio, or when the other traffic on a busy highway ups the noise level, you head over the 85 dB level.

People who work with animals
They nip, bite and scratch, but dirty puncture wounds aren't the only threat facing bird breeders, farmers and veterinarians: they are all at risk of contracting psittacosis (parrot fever).

The usual means of infection is the inhalation of microbes that have entered the air from dried bird faeces or secretions.

Flu-like symptoms usually appear five to 14 days after infection, and may include fever, chills, headache, tiredness, sore muscles, a dry cough, breathing difficulty and chest tightness. Parrot fever can develop into severe pneumonia and could even lead to death.

Without treatment, the fatality rate in humans is 15 - 20%. With timely, appropriate antibiotic treatment, however, risk of death drops to less than 1%.

Farmers at risk for cancer
A recent study showed that farmers are known to be at higher risk of a type of brain cancer known as glioma, although there was no association found between types of farming or farm activities and the disease.

Dr Avima M. Ruder of the National Institute for Occupational Safety and Health believes the association is likely due to farmers' well-documented lower risk of having allergies. Studies have found a reduced risk of cancers-including gliomas-among people with allergies, she explained, probably because their "hypersensitive" immune systems are better able to find and destroy abnormal cells before tumours form.

In the study, she and her colleagues looked at dozens of different factors including pesticide use, type of crops farmed, and length of time living on a farm to determine whether any might account for the increased risk of gliomas found among farmers. They included 288 people with gliomas and 474 healthy controls, all of whom lived on farms in Iowa, Michigan, Minnesota or Wisconsin at age 18 or afterwards.

People who didn't wash up after applying pesticides or who didn't change clothes after using these chemicals were about three times as likely to develop gliomas, the researchers found. Those who lived on farms where corn, oats, soybeans or hogs were raised were actually at lower risk.

Ruder points out that people who don't follow precautions about pesticide use may be less cautious in other areas of their lives as well; she also noted that gliomas can affect a person's memory, so it's possible that the sick individuals had an impaired recollection of their pesticide use practices.

Whether or not the link between taking these precautions and glioma risk was real, she added, "there are other diseases that you can increase your risk for if you don't follow good work practices. People do get poisoned by pesticides."

War correspondents
There is something romantic about journalists and others who face personal danger to report on issues such as wars and genocide, but the price they pay can be high.

Yes, they can be kidnapped, shot or blown up, but even those who return apparently intact may be in trouble. According to an article published in the American Journal of Psychiatry, both male and female war correspondents had significantly higher weekly alcohol consumption than journalists who did not write about wars.

The study also found that, "war correspondents have significantly more psychiatric difficulties than journalists who do not report on war. In particular, the lifetime prevalence of PTSD is similar to rates reported for combat veterans, while the rate of major depression exceeds that of the general population."

Soccer players
In a rather baffling finding, researchers have noticed that Italian soccer players are six times more likely than the general population to develop the degenerative neurological condition amyotrophic lateral sclerosis (ALS).

The New York Times quotes the researchers speculating that ALS may be related to heavy physical exercise. Alternatively, head trauma or exposure to environmental toxins (in the form of fertilisers and herbicides on soccer fields) are also suspected.

Whereas the reasons for the link are unclear, there is little doubt that even with the increased risk, the chance of developing ALS remains very low. So, no reason to stop playing soccer.

Rock stars, computer people and mechanics
If you work with a screwdriver or spend your day behind a computer keyboard, you're in the same risk group as a Jimi Hendrix and Duane Allman (who, according to Rolling Stone magazine, are the two greatest guitarists of all time): you are at risk of developing carpal tunnel syndrome.

This hand-numbing condition usually results from swelling in the wrist caused by repetitive hand motion. The swelling leads to pressure on the median nerve where it passes through the carpal tunnel (in the wrist).

Symptoms of carpal tunnel syndrome include tingling and numbness in the thumb, index and middle fingers. In bad cases it can cause a weakening of the thumb muscles and lead to difficulty gripping objects.

In most cases a bit of rest will do wonders. It is important, however, to get rid of the cause by adapting the way you hold your hands when you type, the way you grip screwdrivers, or by making some changes to your guitar technique.

Coal miners 
Inhaling large amounts of coal dust places people working in coal mines at high risk of developing black lung disease – so called because the lungs appear black rather than pink, according to WebMD.

In severe cases, large coal nodules can form in the lungs, which can obstruct and hamper air flow.

There is no proven treatment for black lung disease, but some of the symptoms can be managed. The ideal would be simply to avoid coal dust altogether, but in most cases that would mean quitting your job.

According to WebMD, inhaling large amounts of coal dust also places you at an increased risk of developing emphysema, chronic bronchitis and chronic obstructive pulmonary disease.

Detergent factory workers
People who work in detergent factories are at increased risk of developing respiratory problems, including asthma, probably from exposure to chemicals contained in detergent.

Exposure to chemicals found in powdered detergent was first recognised in 1969 to cause job-related asthma. Since then, the industry has introduced measures for limiting workers' exposure, although outbreaks of occupational asthma still occur.

However, two new studies suggest that workers with a high exposure were at four times greater risk of itchy nose and sneezing.

Loggers
According to a report released in 2005, the most dangerous job in the US is logging. An estimated 92.4 out of every 100 000 loggers died in 2004, reports CNN.

According to the US National Institute for Occupational Safety and Health (Niosh), "59% of all logging-related deaths occurred when workers were struck by falling or flying objects or were caught in or between objects. Approximately 90% of these fatalities involved trees, logs, snags or limbs."

Tall, heavy and in league with gravity, trees can be extremely dangerous to those who try to cut them down. Niosh outlines a number of tragic case studies in which felled trees dislodged branches or fell against other trees, setting in motion chain reactions ending in fatalities.

It seems there's more than just a "green" case for felling fewer trees.

- (Marcus Low, Health24, updated November 2009)

Sources:
- A hazardous profession: War, journalists and psychopathology. Feinstein et al. 159 (9): 1570. American Journal of Psychiatry.
- America's most dangerous jobs. CNN.
- An A.L.S. puzzle on the soccer field. New York Times.
- Black lung disease. WebMD.
- Logging alert. National Institute for Occupational Safety and Health.
- Accident statistics
- Reuters Health