Outdoor workers exposed to dangerous solar radiation

Thomas Tenkate
We all know that the sun can be a serious workplace hazard when it comes to heat, especially for anyone working outside in the summer. Did you also know that ultraviolet radiation (UVR) from the sun is also a workplace hazard? About 1.5 million workers are exposed to solar radiation in Canada, according to Carex Canada. Reducing the risks from solar UVR and heat exposure should be a daily consideration of both employers and workers. 

Skin cancer is the most commonly diagnosed cancer in Canada, and it is also largely preventable. Carex Canada estimates that in 2014, as many as 7,000 skin cancers were attributed to occupational sun exposure. Sun exposure in general, not just sunburns, contribute to skin cancer, and tanned skin is still damaged skin.  

The risk of heat-related illness for outdoor workers is well defined and continues to be an important issue. Heat stroke is the most deadly form of heat-related illness — workers can die from heat stroke. Other hazardous health conditions caused by heat stress include heat exhaustion, heat cramps and heat rash.  

Sun exposure is a risk factor for both heat-related illness and skin cancer, but UVR and heat are measured in different ways. Feeling the heat outside depends on air temperature, humidity, air movement, and the clothing you are wearing. UVR from the sun is measured by the UV Index. Every day, Environment Canada rates the intensity of UV on a scale from 0 to 11+. When the UV index is 3 or higher, sun protection is recommended. Remember that cool, cloudy days can still have a high intensity of UV. For outdoor workers in Canada, this means that heat is a particular concern in the summer months, but due to our UV index values, UVR is a year-round concern.  

Sometimes control strategies to increase UVR protection can appear to be in conflict with control strategies for heat stress. For example, minimizing UVR exposure can be done through covering up, but long sleeves and pants can sound uncomfortable on a really hot day. However, longer clothing does not increase core body temperatures, according to research by Wade Sinclair from James Cook University in Australia.   

Understanding how to address sun-related heat and UVR exposure together can help workplaces implement a comprehensive and effective strategy to keep their workers safe.   

Both workers and workplaces have an important role to play in reducing the risks of working outside in the sun. Workplaces can address heat and sun safety by working through the hierarchy of controls. While elimination and substitution of the sun are not possible, the following strategies are effective to improve a workplace’s heat and sun safety. 

Policy controls
The main policy control is to develop a heat and sun safety policy that is integrated with the broader occupational health and safety policy of the workplace. Heat and sun safety procedures should also be embedded in the OHS management system of the workplace.  

Engineering controls
Engineering controls include shade structures such as canopies, tress, tents or buildings. This includes natural or portable shade structures and fitting shade to machinery or equipment. Tinting of plant or vehicle windows can be effective, particularly if adding a UV-protective film. Additional UVR-specific engineering controls include eliminating or minimizing reflective surfaces. Heat-specific controls include air conditioned vehicles and rooms for breaks, and insulating plant or equipment to reduce radiant heat emissions.

Administrative controls
Administrative controls include conducting regular hazard and risk assessments, particularly when work activities or job tasks change. It is a good idea to post the daily UV Index, and where possible, schedule work activities outside of peak UV times (11 am to 3 pm). It may also be possible to schedule more physically demanding tasks in the cooler times of the day. For heat-stress, it is important to monitor the humidex or WBGT (wet-bulb globe temperature) and to implement appropriate work-rest cycles, along with having an acclimatization policy for new and returning workers.

An air conditioned or shaded room is helpful for work breaks, as is providing ice or chilled water and encouraging frequent water breaks. It is important to encourage supervisors and managers to be heat and sun safe role models and to practice heat and sun safe behaviors. All workers should be familiar with the signs of heat-stress and should be encouraged to monitor these in their colleagues. Injury reporting and investigation procedures also need to be considered for when there are incidents of excessive sun exposure or heat-related illness. Finally, some workplaces implement incentives or other reinforcement initiatives for heat and sun safety.

Education and awareness
Education and awareness strategies include providing heat and sun safety training to supervisors, managers and workers, along with having regular toolbox talks. These help to raise awareness of the warning signs for heat and sun safety. For UVR, information and training can also be provided to employees to help them effectively examine their own and that of their family members.

Personal protective equipment (PPE)
For personal protective equipment, a wide-brimmed hat, hard hat with a full brim and neck flap are important, along with long sleeves and pants that have a high ultraviolet protection factor (UPF). For heat-specific considerations, loose fitting and breathable clothing is helpful and in some situations, “cool wear” may be beneficial. Sunglasses, eyeglasses or safety glasses with UV-protective lenses are important as is broad spectrum water-resistant sunscreen with an SPF of at least 30.  

Thomas Tenkate is an associate professor and the director of the School of Occupational and Public Health at Ryerson University. He is the project lead for Sun Safety at Work Canada, a national project that is developing heat and sun safety resources to help workplaces implement heat and sun safety programs for outdoor workers. For more information, please visit http://www.occupationalcancer.ca/2013/sun-safety-at-work-canada/.

This article was co-authored by Rivka Kushner, a knowledge broker and research associate at the Occupational Cancer Research Centre at Cancer Care Ontario. She also works on the Sun Safety at Work Canada project.