Occupation safety and health

A relatively new concern that dates roughly to the post-Industrial Revolutionera, occupation health and safety is a field that involves measures to prevent or minimize dangers to people in their places of work, i.e., the office, farm, building site, factory, or store. These hazards generally fall into twocategories: those presented by toxic chemicals and those presented by physical factors.

Perhaps the first recognition of an occupational disease was made by Sir Percival Potts in the 1700's, when he identified cancer of the scrotum as an occupational hazard afflicting chimney sweeps.

In industrialized countries, job-related accidents kill more people every year than any diseases except cancer and heart disease. The National Safety Council (NSC) estimated in 1990 that some 100,000 new work-related illnesses occur every year in the United States and that people who work in the mining, agriculture, construction, and quarrying industries are three to four times morelikely to die than their counterparts in other industries. The NSC also reported in 1990 that industrial accidents led to almost 2 million disabling injuries and approximately 11,000 deaths in the United States.

While it would seem practical to implement strong health and safety provisions in all workplaces, there are several factors that sometimes bar these provisions from going into effect. One of them, not surprisingly, is that companyowners and operators perceive safety and health laws as expensive and unnecessary meddling by the government. Sometimes even the workers themselves resisthealth and safety regulations because they seem overcautious and may interfere with comfort. However, while bureaucracies can be frustrating to deal with, laws such as those imposed by the Occupational Safety and Health Administration (OSHA) and its subsidiary agencies can potentially save millions of dollars in worker compensation claims, sick time, and law suits every year.

Toxic Chemicals

Many industrial processes require the use of toxic chemicals as raw materials, generate toxic chemicals as byproducts, or even produce toxic chemicals that will be used for various purposes. The ideal approach to this health risk is called mitigation, i.e., reducing the risks involved. The most effective ways to mitigate worker exposure to toxic chemicals are process or equipment modification, local exhaust ventilation, elimination or substitution of a substance, isolation or enclosure, and providing personal protective equipment andclothing if the substance's harmful effects cannot be minimized by the othermeans.

The most common health risks that workers face are caused by inhaling dust from coal, grains, clay, quartz, asbestos, silica, fungal spores, and metals; by being exposed to radiation, whether from the sun or ionizing sources; and by coming into contact with such common industrial chemicals as lead, beryllium, cadmium, arsenic, benzene, or vinyl chloride, which all can cause severe damage to all organs of the body when inhaled, touched, or ingested.

As one would imagine, the most prominent effect of dust inhalation is respiratory disease. On a long-term basis, dust inhalation can contribute to asthma,bronchitis, and a variety of inflammations of the lung and the chest wall. The long-term effects of inhaling asbestos were discovered to be particularlyserious. This mineral was greatly valued for its;insulating abilities and durability. However, in the 1960's it became clear that worker who inhaled asbestos fibers released during all types of construction work had unique and serious ailments of their lungs and chest wall. These disorders included a devastating form of cancer known as mesothelioma.

Two very useful industrial metals--beryllium and cobalt--were also found to cause severe disease in workers who inhaled dusts of those materials. Now thatthe diseases are understood, industries have designed processes to minimizeexposure of workers to these dusts. Also, if the diseases are recognized early, it is possible to minimize further damage, or even to reduce the damage ina given worker.

Inhalation of chemical fumes is both a short-term and a long-term risk. In the first 48 hours, chemical exposure to the lung can cause swelling of the larynx, both asthma and bronchitis, pneumonia, and the devastating adult respiratory distress syndrome. The latter is a form of shock that can be fata. Weeksor months after a severe short-term reaction, a worker may develop asthma, bronchitis, or other chronic disorders.

Smoke and fumes generated by fires present specific hazards. These can affectboth fire fighters and workers at an industrial plant where a fire occurs. For that matter, toxic smoke can spread outside the grounds of a plant and create an environmental catastrophe. The worst modern example of this was a firein a chemical plant in Bhopal, India, in 1984. A toxic chemical called methyl-ioscyanate was released from a storage tank. Some 2000 people died and perhaps 250,000 others suffered some ill effects. Many people have ongoing healthproblems from that single disaster.

Smoke inhalation can cause damage either through burns (largely in the upperairway) or through the effects of specific toxic substances. There is no specific medical cure for smoke inhalation. In severe cases, a worker may be placed in an intensive care unit for general physiologic support.

Physical Injuries

The largest number of injuries recorded by U.S. government statistical programs occur in the construction and transportation industries, with manufacturing and agriculture reporting somewhat fewer injuries. Statistics about occupational deaths are more precise than those for non-fatal injuries. They indicate that motor vehicle accidents are the most common cause of death on the job,with machinery, homicide, falls, and electrocution accounting for substantial numbers of deaths as well.

Injury rates fluctuate for various reasons. For instance, injuries in the construction industry declined consistently in the 1940's and 1950's; in about 1975, the trend started up again. Companies that increase their rate of hiringnew workers report increased rates of injury, as well. And some studies indicate that increased productivity in certain jobs seems associated with increased rates of injury, presumably because of lessened emphasis on safety procedures with a heavy workload.

Workplace homicides often occur in the course of robberies or other crimes, and they generally occur at night. Police, taxi drivers, and other security workers are the most common victims of workplace homicide.

To lessen the risk of accident or injury present by physical factors, employers can offer training, for instance, on how to operate machinery or lift heavy loads properly to avoid back strain. Some organizations present "back school" programs, either to all workers or to workers with a history of back problems. These programs are popular with workers, but careful studies have not demonstrated that they actually lead to reduced back injuries among the "graduates."

Allergies to or long-term contact with irritating chemicals can cause dermatitis, while exposure to serious diseases such as AIDS, leptospirosis, and brucellosis, among many others, are dangers for people who work with blood, rats,and livestock, respectively. Many people are also hurt every year by liftingheavy loads; running or working around machinery unsafely; working outdoorsfor too long or with too little protection in sunny, windy, or hot conditions; receiving electric shocks; and sustaining carbon monoxide poisoning.

Virtually every body system can be afflicted with an illness traced to an occupational exposure.

Eye disorders can range from eye strain to cataracts. Eye strain is often seen in workers who use computer terminals. If terminals are placed correctly and if the worker has the appropriate glasses or contact lenses, eye strain tends to be a manageable problem. Ocular allergies are fairly common, and can becaused by a host of substances in the workplace. A solvent called trinitrotoluene (TNT) is well-known for causing cataracts in workers who are exposed toit on a regular basis. Workers are also at risk if a wide variety of chemicals splash into their eyes, or if sharp materials are driven into the eyeball.For this reason, safety goggles are among the most important pieces of equipment for many workers. In any location where liquids might splash into the eye, safety showers are a must.

Noise is another risk to the health of workers. According to OSHA regulations, a workplace with an average noise level of 85 decibels (equal to the noiseof a loud party) is required to provide hearing protection against the effects of chronic noise exposure. Another cause of hearing loss is a sudden, veryloud noise, as with an explosion.

Exposure to a number of common industrial chemicals can lead to serious blooddisorders, including different types of anemia, clotting abnormalities, andeven a precursor to leukemia. These problems sometimes result from sudden, intense exposure (as from a spill), or from long-term exposure to small amountsof the chemicals. Among the chemicals involved are lead, cobalt, turpentine,and benzene.

Perhaps a wider variety of chemicals can cause severe kidney disorders. Metals such as arsenic, cadmium, chromium, lead, and mercury are key problems. Carbon tetrachloride, chlorophorm, and other hydrocarbons are other toxic agentsfor the kidney.

Because the liver normally metabolizes many toxic agents (such as alcoholic beverages), it is also affected by a wide variety of chemicals, similar to thelong list of chemicals that can damage the blood or the kidney.

Hazards of Stress

Although occupational health related to manufacturing, mining, and other heavy industries seems dramatic, office workers and other people in "white-collar" jobs also experience job-related health problems. Although all fast-paced jobs would seem to be stressful, the problem is more complex than that. The most prominent cause of such problems appears to be psychologic stress caused by lack of control of the job itself or pace of work, poor management practices, deadlines, overly long hours, or discrimination in many forms.

These work conditions are linked very strongly to the development of high blood pressure, heart attacks, and the development of dangerous plaques in the arteries. Apparently these disorders result from the body's long-term responseto high levels of stress hormones in the blood. Digestive disorders, especially peptic ulcers, are other physical diseases that increase based on workplace stress.

Highly stressed workers seem to suffer from increases in neck, shoulder, andback pain. The effect of psychologic stress on these pains is as strong as the effect of heavy physical loads. A related disorder, carpal tunnel syndrome,is likewise most likely to occur in highly stressed workers. Because of somereported links to heavy computer use, computer makers have attempted to develop ergonomically "correct" keyboard and mouse designs. Similarly, some office chairs and work stations are said by their designers to reduce strains leading to some or all of these musculoskeletal problems.

Carpal tunnel syndrome is actually one disorder among a wider category knownas repetitive stress disorders (RSD's.) RSD's can occur among any worker whomust do a repetitive task at a pace determined by an assembly line or other outside agent. Meatpackers who are expected to make one particular type of cutall day suffer a variety of RSD's, depending on the exact motions they havebeen making. In plants where a packer is responsible for a number of cuts ona single animal, RSD's are much less common. Although RSD's have physical causes and physical manifestations, some authorities believe they are strongly stress-related.

Sometimes workers--either industrial or office-based--develop back problems that require surgery. Back surgeons have learned that workers from high-stresssituations have much poorer outcomes from spine surgery than do other people. With no obvious physical explanation, they believe that a psychologic mechanism reduces the body's ability to heal after surgery.

Some authorities believe that workplace stress lowers immune resistance to infectious diseases such as colds and flu, although the evidence is relativelyweak.

Shift Work

A large and probably increasing proportion of workers do their work well outside the typical "9-to-5" work day. Some workers consistently work evening orovernight shifts, while other job involve "rotating" shifts, moving from dayto evening to overnight work periodically. Shift work disrupts the normal sleep-wake cycles found in all humans and leads to a number of well-documented health problems.

The most obvious effects are sleepiness and poorer work. Shift workers oftenhave very brief episodes of sleeping on the job and often are not aware of this. All of this leads to a significant increase in accidents and errors amongshift workers.

Overall, people who do shift work over long periods of time report more health problems overall. They tend to use both tobacco and caffeine more often, and they are at greater risk for cardiovascular problems.

Effects on Fertility

Both men and women can be affected adversely through workplace exposures. Menexposed to lead, certain pesticides, and solvents may be less able to make awoman pregnant. Also, men exposed to radiation or who work consistently in very hot places may have similar problems. Because of the intricate control offemale fertility, experts believe that many types of occupational exposure can have deleterious effects. However, studies are rarely conclusive. Causes of spontaneous abortion or fetal death are more clear cut. Among them are lead, the solvent ethylene glycol in semiconductor manufacturing plants, and veryheavy labor. Lead is also the most clearcut culprit in causes of slow fetalgrowth rates and birth defects. Many other substances have come under suspicion, but the evidence is not conclusive.

Health Care Workers

Health care in the United States accounts for nearly 15% of the economy, andit employs millions of people who make contact with patients or their body fluids--doctors, nurses, paramedics, technicians, and the like. Among the greatest risk to these workers is the spread of diseases from contact with blood or other body fluids. Among these are HIV infection and hepatitis A, both of which are serious chronic diseases that can be fatal. As with other occupational health risks, prevention is the most effective approach to minimizing therisks. All health workers should wear protective gloves when touching patients or their body fluids and should avoid being stuck with needles bearing theblood of a patient. Researchers have introduced an effective vaccine againsthepatitis A, and workers are gradually receiving the necessary doses.

Ironically, protective gloves themselves are now implicated as a cause of occupational disease. The most effective and economical gloves are made of latexand come impregnated with powder to make them easier to slide on and off thehand. Unfortunately, a substantial minority of health care workers have developed significant allergies to latex after many years of exposure to the material. Gloves are available in other materials, but overall they are more expensive and somewhat less convenient to use. As with other occupational allergies, sometimes the only solution is for a person to give up their occupation and remove all contact with the material.

Another concern for health care workers is specific exposures to materials that may reduce their fertility. Oncology nurses exposed to anticancer drugs, operating room personnel exposed to anesthetic gases, and personnel who are exposed to ethylene oxide in sterilizers may all suffer reproductive problems.

Laws, Regulations, and Prevention

Since the Industrial Revolution, during which a period of rapid economic growth and the introduction of mechanical and technical inventions led to many thousands of injuries and deaths from poor working conditions and lack of safety provisions, there have emerged entire state and federal bureaucracies dedicated solely to health and safety in the workplace. However, it was not until1970 that the Occupational Health and Safety Act was passed. This, in turn, established the National Institute for Occupational Safety and Health and theDepartment of Labor's powerful OSHA, which supports reduction of workplace hazards, establishes training programs, creates mandatory safety and health standards, and provides for occupational and health research.

Because it is literally impossible to have a modern economy with workplace hazards, a key challenge is to ameliorate the hazards. Experts in the field ofindustrial hygiene attempt to document potentially hazardous workplace conditions and then devise strategies to minimize them. In some cases, this entailschanges in the workplace, such as measures to remove toxic gases or dusts from the workplace.

Protective devices ranging from goggles and earmuffs to respirators protect against both chronic hazards and accidents. Businesses are reluctant to purchase them, because they do not contribute directly to profitable production. Workers are often reluctant to wear protective equipment because it can be uncomfortable. Because of this mutual reluctance, OSHA and other agencies sometimes require the use of certain types of equipment.

Experts also acknowledge that worker education and training are essential components of a safe workplace. OSHA requires specific training for workers using hazardous chemicals in the workplace, while other hazards are governed farmore loosely. Some workplaces offer everything from "back schools" to stressmanagement workshops to improve the health of their workers.

Other government agencies have written regulations to deal with specific hazards. For instance, the United States Department of Transportation has writtenregulations concerning work hours of long-distance truck drivers. These regulations provide a maximum number of hours a trucker can drive in a day, minimum requirements for rest periods and sleeping, and the like; truckers are required to keep a detailed log.

In the 21st century, as in the 20th, the greatest challenge will be making sure that occupation health and safety measures keep pace with the rapid development of new technologies in the workplace.

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