Position paper on diesel particulate and its potential for occupational health safety issues
Position paper on diesel particulate and its potential for occupational health safety issues
Introduction
Although the negative health implications of gaseous portion of diesel emissions appear in the previous literature, only limited research have indicated that the particulate component of diesel exhaust has the potential to cause several health problems. Additionally, diesel particulate is associated with visual, malodor, and nuisance pollution. There are readily available methods for measuring workplace exposure to diesel particulate and control technology that help reduce exposure. Drawing form epidemiological and animal studies, it is evident that diesel particulate is a potential carcinogen. However, owing the lack of informative literature, particularly concerning past exposure conditions, this position paper addresses the occupational health issues related to diesel particles. There is a possibility that just as the case with low potency substances, the issues may not receive adequate attention owing to the lack of adequate exposure data and control confounders in studied populations.
Emerging trend among the occupational health community is to take a pragmatic approach to measure and control irritant, noxious and malodorous releases without trying to define a dose response based on exposure standards. Despite the lack of defined dose response, field experience has showed that controlling exposure to below 0.1mg/m3 DP reduces the effects of irritation remarkably. It is believed that maintaining such level would significantly reduce lung cancer.
The invention of ignition engine 115 years ago by Rudolph Diesel significantly had a significant contribution to productivity in many nations (US EPA, 2012). In terms of occupational, diesel particulate has negative impacts as it expose large number of workers to complex mixture of adsorbed organics, toxic gases, and particulate components found in raw exhaust emissions. The gaseous emissions of diesel largely consist of same gases found in air, such as oxygen, nitrogen, water vapor, and carbon dioxide. However, emissions from diesel engine contain very small particles, which react rapidly in with body organs to form clumps. Due to their graphitic nature and high surface area, these particles have the ability to absorb large amounts of hydrocarbons coming from lubrication oil, fuel, and the compounds formed in the combustion process. In relation to occupational health safety, the minute particle of diesel particulate is important because it access deep parts of the lungs. Large amount of particulate is a major concern as it can lead to toxic effect.
Measuring diesel particulate
The most effective and advanced methods involves capturing the submicron portion of aerosol in the workplace and measuring the main component of diesel particulate, which is carbon.
Hazards resulting from diesel particulate
Exposure to toxic gases and small diesel particulate of diesel exhaust finds their way into the lungs. The particles of diesel exhaust are too minute that they can penetrate into the lungs resulting into a range of health problems. Exhaust from diesel engines and many particles that it contains have the potential of causing mutations of cells resulting into cancer. Some studies indicate that long-term exposure to diesel exhaust particles poses the highest risk of cancer compared to any other air contaminant. The potential longer effects of exposure to diesel emission include stroke, cardiovascular disease, emphysema, high blood pressure, and cancer.
Exposure to diesel emission can have immediate implications. Exhaust form diesel engines can cause irritation to the nose, eyes, throat and lungs, and it causes headaches, coughs, nausea and lightheadedness. An experiment conducted on human volunteers indicates that the diesel exhaust makes people with allergies more susceptible to materials to which they are allergic, such as pollen and dust. Continued exposure to diesel exhaust also has the potential of causing lung inflammations in the lungs, which may result into chronic respiratory symptoms and increase the intensity or frequency of asthma attacks. Diesel exhaust produces fine-particle pollution. Clinical evidence indicates that elderly people with asthma, emphysema, and chronic lung and heart diseases are particularly sensitive to fine-particle pollution. Because children do not have a well developed lungs and respiratory systems, they are more susceptible to fine particles compared to healthy adults. Exposure to fine particles can increase the chances of childhood illnesses and can reduce lung function in children.
While medical research associated with exposure to diesel particulate remains scant, and may not be resolved in the near future, there is no doubt regarding the irritant nature of diesel emissions in confined atmospheres including factories and mines. Based on these health effects, controlling diesel emission to reduce irritation in the workplace may potentially reduce the long-term effects of constant exposure.
Potential for exposure
The potential for exposure to diesel particulate exists in workplaces where workers operate diesel equipment. In most case, operating diesel engines in open environment significantly reduces the potential for excessive exposure. However, there is significant risk exposure where diesel equipment is operated in confined areas, such as cool room, underground mines, and ships’ holds.
Available controls
Several control technologies have been adopted over the past years, especially for diesel engines operating on confined areas. Proven control technologies include:
- Ventilation
- Low emission engines
- Low fuel emission
- Exhaust filtration
- Air conditioned
- Operating practices
- Workforce education
- Personal protective equipment
References:
US EPA (2012): Health assessment document for diesel engine exhaust. US Environmental Protection Agency, Document EPA/600/8-90/057F
