Abstract

This study was designed to test whether the total objective adverse work and environmental conditions, expressed as the ergonomic stress level (ESL), would predict occupational injuries over a 2-year period. The study population consisted of 4,096 men from 21 factories in six industrial sectors who were studied as part of the Israeli Cardiovascular Occupational Risk Factors Determination in Israel (CORDIS) Study, 1985-1987. The ESL (assigned four levels, 1-4) was based on an ergonomic assessment which covered 17 risk factors pertaining to safety hazards, overcrowding, cognitive and physical demands, and environmental stressors. The ESL was found to be a highly reliable measure and stable over a period of 2-4 years. The incidence of injuries among workers in low ESL conditions (level 1) was 10.3%. It increased with higher ESL's: 11.7% in level 2 (relative risk (RR) = 1.13, 95% confidence interval (CI) 0.86-1.50); 21.6% in level 3 (RR = 2.09, 95% CI 1.68-2.62); and 23.8% in level 4 (RR = 2.31, 95% CI 1.85-2.88). After adjustment for age, job experience, educational level, managerial status, and occupational status (white/blue collar), injury occurrence was significantly elevated for those at level 3 (adjusted odds ratio (OR) = 1.46, 95% CI 1.12-1.91) and level 4 (adjusted OR = 1.81, 95% CI 1.39-2.37) but not for level 2 (adjusted OR = 0.87, 95% CI 0.65-1.18). The authors conclude that adverse work and environmental conditions, objectively assessed, can predict occurrence of occupational injuries.