Understanding the Health Risks of Working Around Asphalt
One of the materials that are the most frequently used in road construction and roofing in the United States is asphalt. Thousands of workers are exposed to hot asphalt or inhaling fumes of asphalt every day on the job sites. Although asphalt is used in the construction of the roads that we drive on and the roofs that cover our homes, most individuals have a burning question: Do asphalt fumes cause cancer?
This article describes the nature of asphalt fumes, the science surrounding the effects of the fumes on human health, and the safety measures that can be adopted by workers.
What Are Asphalt Fumes?
Asphalt or bitumen is a black, sticky, and petroleum-based substance. It is primarily applied in road paving, roofing and waterproofing. Asphalt produces fumes when it is heated to high temperatures, typically between 250degF and 500degF, and is a combination of gases and small airborne particles.
These fumes can include:
- Polycyclic aromatic dibenzo-dioxin (PAHs).
- Volatile organic compounds (VOCs).
- Hydrogen sulfide.
- Sulfur oxides.
Workers who breathe in these fumes or touch them on their skin are exposed to chemicals which may have both short- and long-term health consequences.
Short-Term Health Effects of Asphalt Fumes
Short-term symptoms are the first to manifest themselves to most individuals who deal with asphalt.
Such symptoms tend to occur during or immediately after exposure and may involve:
- Headaches
- Nausea or dizziness
- Throat and eye irritation
- Skin rashes or burns
- Coughing or chest tightness.
These symptoms usually pass away when an individual moves out of the workplace or the exposure has been terminated. But with time, being exposed to asphalt fumes without protection may cause more severe health risks.
The Big Question: Can Asphalt Fumes Cause Cancer?
The connection between asphalt fumes and cancer is not a completely simple answer that has been the topic of study over decades.
What the Research Shows
According to the National Institute of Occupational Safety and Health (NIOSH) and International Agency of Research on Cancer (IARC) claim that asphalt fumes are possibly cancer causing to human beings (Group 2B).
This means that:
- It is not well established that asphalt fumes lead to cancer in human beings.
- It is adequately demonstrated that some of the asphalt fumes may be cancer-causing in animals.
Other investigations have reported increased lung, bladder, and skin cancer rates in asphalt workers, but it is hard to distinguish the impact of asphalt fumes on these diseases and other exposures such as cigarette smoke or diesel exhaust, which are widespread in construction areas.
The Role of PAHs
One of the most worrying chemical substances in asphalt fumes is polycyclic aromatic hydrocarbons (PAHs). Certain PAHs are carcinogens, i.e. they might damage the DNA and cause cancer.
But the concentrations of PAHs in current paving grade asphalt are normally significantly lower than those in older or coal-tar based products.
Are Roofing Workers at Higher Risk?
Yes. Asphalt roofing is normally heated to a higher temperature compared to paving asphalt and it emits more fumes. Consequently, roofers are able to work under more exposure levels- particularly in places that have poor ventilation.
A number of studies have shown that roofing workers are a little more likely to develop some kind of cancer than the rest of the population. This does not imply that asphalt fumes are certain causes of cancer but it does indicate that there is a necessity of tighter exposure controls and personal protection.
How Workers Can Stay Safe
Although it is not clear whether the threat of cancer due to the fumes of asphalt is real, there are some obvious reasons to reduce the exposure. To this day, inhalation of fumes in the long run can still damage your lungs and skin.
The following are some of the safety tips:
Use Proper Ventilation
Where there is work in a closed space or in an enclosed area, there must be proper ventilation. Reduce fume build-up is done by fans, exhaust systems or open areas.
Wear Protective Equipment
- OSHA approved dust masks or respirators.
- Long sleeve clothes and heat-resistant gloves.
- Sight protection to avoid irritation.
- Protective creams on bare skin.
Monitor Air Quality
To eliminate exposure to asbestos at work, the employers are expected to check the air at work to make sure that the exposure is not exceeding the acceptable exposure limits set by OSHA.
Avoid Overheating Asphalt
Storing asphalt at the desired temperature decreases the amount of fumes released to the atmosphere.
Practice Good Hygiene
Wash hands and face before eating, drinking or smoking. Wash dirty clothes and take a shower after shifts to avoid contact between the skin and dangerous chemicals.
Regulations and Worker Protection in the U.S.
There are special recommendations that are given by the Occupational Safety and Health Administration (OSHA) and NIOSH to regulate the exposure to asphalt fume at the workplace.
The employers have the responsibility of ensuring that:
- Hazards associated with asphalt are well trained to the workers.
- Protective equipment is offered and put on properly.
- Ventilation and air monitoring systems are upheld.
There are also states that have more stringent regulations on air quality and limits of exposure at the work place, such as in California.
The existing scientific evidence points that asphalt fumes are likely to cause a cancer risk but the interrelation is not yet certain. The threat seems to be greater to employees who experience unprotected prolonged exposure- particularly roofers and paving workers.
However, in the case of contemporary safety measures, adequate ventilation, and protective measures, the danger can be minimized significantly. To the average individual who only comes in contact with asphalt every now and then (such as road users or people living around them), the exposure levels are too low, and that does not raise any concern.