Mining and oil and gas extraction
The mining industry still has one of the highest rates of fatalities of any industry. There are a range of hazards present in surface and underground mining operations. In surface mining, leading hazards include such issues as geological stability, contact with plant and equipment, blasting, thermal environments (heat and cold), respiratory health (Black Lung) In underground mining operations hazards include respiratory health, explosions and gas (particularly in coal mine operations), geological instability, electrical equipment, contact with plant and equipment, heat stress, inrush of bodies of water, falls from height, confined spaces. ionising radiation
According to data from the 2010 NHIS-OHS, workers employed in mining and oil and gas extraction industries had high prevalence rates of exposure to potentially harmful work organization characteristics and hazardous chemicals. Many of these workers worked long hours: 50% worked more than 48 hours a week and 25% worked more than 60 hours a week in 2010. Additionally, 42% worked non-standard shifts (not a regular day shift). These workers also had high prevalence of exposure to physical/chemical hazards. In 2010, 39% had frequent skin contact with chemicals. Among nonsmoking workers, 28% of those in mining and oil and gas extraction industries had frequent exposure to secondhand smoke at work. About two-thirds were frequently exposed to vapors, gas, dust, or fumes at work.
Healthcare and social assistance
Beekeepers often wear protective clothing, for OHS reasons.
Healthcare workers are exposed to many hazards that can adversely affect their health and well-being. Long hours, changing shifts, physically demanding tasks, violence, and exposures to infectious diseases and harmful chemicals are examples of hazards that put these workers at risk for illness and injury. Musculoskeletal injury (MSI) is the most common health hazard in for healthcare workers and in workplaces overall. Injuries can be prevented by using proper body mechanics.
According to the Bureau of Labor statistics, U.S. hospitals recorded 253,700 work-related injuries and illnesses in 2011, which is 6.8 work-related injuries and illnesses for every 100 full-time employees. The injury and illness rate in hospitals is higher than the rates in construction and manufacturing – two industries that are traditionally thought to be relatively hazardous.
Occupational exposures in dentistry
Dental professionals and their teams encounter multiple exposures daily to occupational hazards in dentistry. These occupational exposures are detrimental to their health, especially when they are chronic in nature.
- Exposure to noise: Any undesirable sound present in the working environment is referred to as occupational noise. According to the OSHA, when working five days a week in any environment, the international standard of the eight-hour daily occupational exposure should not be greater than 85 decibels (dBA), and anything above this could cause noise-induced hearing loss. Hearing loss due to irreversible injury to the inner ear from chronic, cumulative exposure to loud sounds is called noise-induced hearing loss (NIHL). Buzzing and ringing of the ear, also called tinnitus, and dulled hearing are symptoms of NIHL. Several health problems arise due to overexposure to loud noises such as stress, disruption in sleep patterns, cardiovascular disorders, anxiety, fatigue, and depression. Dental professionals are exposed to noise generated by a wide variety of instruments like ultrasonic scalers, suction, and air rotor handpieces. The recommended maximum exposure limit to sound in an 8-hour workday is 85 dBA. In a study, unobstructed suction noise levels had a range of 75–79 dBA, while obstructed suction had a noise level of 96 dBA, and it was recommended that professionals should not have an exposure of more than 1 hour in such a workplace. High-intensity sounds from ultrasonic scalers range between 69 and 84 dBA within the safe 8-hour limit for occupational noise. Threshold shift, the reduction in hearing due to reduced sensitivity level of ears due to noise exposure, occurs due to the use of an ultrasonic scaler, and although this is found to last between 16 hours to almost 2 days, it could cause irreversible damage. In a study conducted in the Dental School of Prince of Songkla University, Thailand, noise annoyance in the dental clinic has been reported by 80% of dental students. The highest percentage of noise dose exposure is found in clinics for pediatric patients.
- Exposure to inhalational anesthetics: Several inhalational anesthetic agents are used in dentistry nowadays like isoflurane, sevoflurane, desflurane, and halothane. But we are most concerned about gaseous sedative, nitrous oxide. Long-term exposures to nitrous oxide may lead to adverse effects on human health such as infertility, neurologic disorders, blood disorders, and spontaneous abortion. Researchers believe that when operating rooms without proper ventilation systems have high non-scavenged gas exposures, the risk of spontaneous abortion increases. It is found that despite intact scavenging systems in dental clinics, sometimes nitrous oxide exposure exceeds the NIOSH recommended limit of 25 ppm by more than 40 times. NIOSH advises dental professionals to use additional ventilation or increase air circulation in the operating rooms to tackle the high nitrous oxide exposure.
- Exposure to elemental mercury: The most likely source of exposure to elemental mercury for dental professionals is mercury release in dental amalgam restorations. Due to prolonged practice in the field of dentistry and working with amalgam there is a significant exposure to mercury among professionals. Inhalation of Hg leads to its absorption in the lungs and accumulation in kidneys, and evidence suggests that dental professionals have higher urinary mercury levels. About 84.9% of dental practitioners among those attending a health screening program in the annual ADA session in San Francisco, California, were found to restore teeth with 1-200 dental amalgam restorations in a week, and about 4.2% did a minimum of 50 dental amalgam fillings in a week. Minute quantities of elemental mercury elevate the Hg concentrations in dental clinics, such that it poses threat to human health. Mercury vapors and elemental mercury remain in furniture, floors, clothes for years if not cleaned properly, and contribute to being a chronic source of exposure. The limit for elemental mercury vapor in workplaces is 0.05 mg/m3 as recommended by OSHA, especially for workers working 40 hours in a week for 8 hours per day, and that for elemental mercury vapor in workplaces set by NIOSH is 0.05 mg/m3 for a work shift of 10 hours. Inhaling elemental mercury vapors lead to serious health consequences in humans. Acute exposure to elevated levels to Hg leads to headaches, insomnia, irritability, memory loss, and slow sensory and motor nerve function along with depressed cognition, renal failure, chest pain, dyspnea, and impaired lung activity. Chronic exposures to elemental mercury lead to hypersalivation and erethism. Several studies show the risk of spontaneous abortions and birth defects in infants on elemental mercury exposure. Elemental mercury has a reference concentration of 0.0003 mg/m3, and when exposures are greater than this level, the possibility of harmful consequences to health increases.