An occupational health risk index: definition, description and mapping at municipality level

Objectives: to develop an occupational health risk index that can help to introduce the occupational risk component into epidemiological studies and assess the level of occupational risk in Italian municipalities useful for supporting prevention measures. Design: definition of a municipal index as a combination of occupational and territorial indicators derived from national registers of occupational data and environmental archives. Setting and participants: the index composition is based on data on work injuries, occupational diseases and workers exposed to carcinogens in the years 2015-2019 available at the municipal level, as well as data on municipalities hosting sites of national interest for environmental remediation ( SIN) and those in which big industrial facilities (GIE), registered as pollutant emitters, are located. Main outcome measures: standardized rates of occupational injuries and occupational diseases occurred in Italian municipalities were calculated from data collected by the Italian National Institute for Insurance against Accidents at Work (Inail) in relation to the working-age population (1569 and 15+ for injuries and occupational diseases, respectively), estimated by the Italian National Statistical Institute (Istat) in 2018. In addition, data from the National Information System on Occupational Exposure to carcinogens (SIREP) were included, from which raw rates were calculated at municipal level. Finally, two other indicators were included, describing the presence/absence of a SIN and the number of GIEs industrial facilities in each municipality. The index of occupational health risk (INDORS) is calculated by summing standardised values of the above five indicators as a continuous variable and it was also classified by quintiles of population as a categorical variable. The association between cause- specific mortality and INDORS levels was evaluated using data on mortality occurring in 2015. Results: during the observation period 2,011,457, 131,353 and 140,183 events were recorded for injuries, occupational diseases and workers exposed to carcinogens, mainly among male workers. A municipal map of INDORS levels (1-5) shows a strong South-North gradient, in line with the Italian industrial geographical context. The contributions of the SIN and GIE indicators are higher in the hot spot municipalities located in the Southern regions and islands. Among the municipalities analysed 1,099 were classified in the lowest risk level, 1,331 in the low-medium level, 1,619 in the medium level, 2,621 in the medium- high level and 1,284 in the highest risk level. The index shows a direct correlation with accidental mortality and an inverse correlation with allcause and malignant neoplasm mortality. Conclusions: the proposed index can be useful to introduce the occupational risk dimension in ecological studies and results as a flexible tool to rank Italian municipalities in terms of occupational risk.