Climate Change and Worker Health and Safety

You may be aware that climate change is affecting sea levels, weather patterns, and animal habitats—but have you thought about how it could affect the hazards your workers are exposed to? Late last year, the National Institute for Occupational Safety and Health (NIOSH) updated its 2009 framework for identifying climate-related occupational hazards based on review and assessment of peer-reviewed literature from 2008–2014.

Read on to learn about four areas, drawn from NIOSH’s updated framework and the work of Cal/EPA’s Climate Action Team (CAT), and how each might affect California employers and workers.

Rising Ambient Temperatures

CAT predicts that average daytime temperatures will rise steadily throughout this century. Although the overall increase by 2030 is predicted to be around 2 to 3 degrees Fahrenheit (ºF), the effect will be more dramatic than just an increase in average temperatures and will increase the need for employer vigilance in heat illness prevention.

Climate change is already leading to:

• More extreme heat events. According to the Centers for Disease Control and Prevention (CDC), an extreme heat event occurs when the summertime temperature is “substantially hotter and/or more humid than average for that location at that time of year.” For some parts of California, these may fall within the National Weather Service criteria for an Excessive Heat Warning or Advisory, which is issued when an extreme heat event (a “heat wave”) is expected within the next 36 hours. These warnings are issued when the heat index is predicted to be 105ºF or greater for 2 or more consecutive days. However, in northern California, much lower temperatures may constitute extreme heat events, leading to an increased risk of heat illness.
• Higher nighttime temperatures. As temperatures rise, nights will also be warmer. Employers need to be aware of the heat index even at night and may have to put precautions in place against heat-related illness for outdoor workers.
• Hotter urban areas. The “urban heat island effect” occurs as a result of pavement and building materials that absorb heat during the day and then release it slowly overnight. As a result of this phenomenon, daytime temperatures in urban areas are generally 1 to 6°F higher than in rural areas. Nighttime cooling in an urban heat island is also much less dramatic than in rural areas, leading to nighttime temperatures that can be as much as 22ºF higher than rural nighttime temperatures.

Changes in the Built Environment

As average temperatures climb, look for more incidences of:

• Sick building syndrome. As the need for—and the cost of—air-conditioned buildings goes up, buildings will be constructed with more insulation and tighter building envelopes. This helps hold down climate control costs but increases the risk of indoor air quality problems and resulting illnesses (called “tight building syndrome” or “sick building syndrome”). Tight buildings can also lead to greater radon exposure.
• Indoor heat exposure. In buildings that aren’t climate controlled, including many industrial workplaces, workers may be exposed to higher temperatures indoors, increasing their risk of heat-related illness.

Extreme Weather

Longer periods of drought can cause water shortages and wildfires, which may affect business operation and worker safety and health.

• Wildfires. Expect more and larger wildfires that are more difficult to control. In addition to the direct fire threat, smoke from wildfires can increase air pollution, affecting the health of workers.
• Lightning. Lightning strikes are expected to multiply as a result of climate change. This increases both the risk of lightning strike for outdoor workers and the incidence of wildfires. Lightning causes about half of all wildfires.
• Floods and landslides. When it does rain, expect storms to become more intense, boosting the risk of both flooding and landslides.

Vector-Borne Diseases and Expanded Habitats

Dry conditions make the spread of some diseases more likely. In particular, valley fever is carried in surface dusts, and the disease is already endemic to California’s Central Valley.

Hotter, drier conditions have also expanded the range of insects that carry disease, including mosquitos and ticks, leading to wider exposure, especially for outdoor workers. It may also result in the introduction of new diseases, like dengue virus. Increased use of pesticides to control insect vectors may place workers at greater risk for exposure.