Extreme temperatures and workplace injuries by economic sectors in Santiago, Chile, from 2012-2019

Climate change increases extreme temperature events, posing critical risks to occupational safety. However, quantitative evidence for Latin America remains scarce. This study estimated relative risks (RR) and occupational injury burden associated with extreme heat and cold in Santiago Metropolitan Area (SMA), Chile, across economic sectors and demographic groups.

A time-stratified case-crossover study (2012-2019) analyzed 603,676 occupational injuries using distributed lag non-linear models (DLNMs) with conditional quasi-Poisson variance to capture non-linear exposure-response associations and delayed-lag effects (5-day lag), controlling for humidity, PM_2.5, and ozone. Risks at the 2.5th (4.8 °C) and 97.5th (23.4 °C) percentiles were compared to the all-industry Minimum Injury Temperature (10.7 °C).

Extreme heat increased injury risk in Hotel (RR=1.36; 95% CI: 1.09-1.70) and Transportation (RR=1.25; 95% CI: 1.02-1.53) sectors, affecting males (RR=1.30; 95% CI: 1.12-1.52) and females (RR=1.40; 95% CI: 1.20-1.65). Extreme cold increased risk in Other Industrial Activities (RR=1.18; 95% CI: 1.06-1.32) and Construction (RR=1.12; 95% CI: 1.02-1.24). Overall, 5,542 injuries were attributable to non-optimal temperatures. Workers aged 25-34 showed the highest heat (RR=1.43; 95% CI: 1.22-1.68), whereas workers aged 55 and older were most vulnerable to cold (RR=1.14; 95% CI: 1.04-1.24).

Extreme temperatures elevate occupational injury risks in a Latin American metropolitan setting, displaying differential vulnerability across sectors and demographic profiles. These findings underscore the urgency of integrating climate-based early warning systems into regional occupational health policies.