Análise do efeito do estresse térmico por calor na produtividade de operadores em uma fundição

Abstract

Ergonomics seeks in essence to adapt the work to the individual, using various tools to achieve this goal, including environmental analysis. The characteristics of the environment such as noise, temperature and lighting can influence the work of an employee, and therefore need to be evaluated to assess its effect on the health of workers and their working ability. The thermal stress caused by heat is the condition where both the physiological system as the psychological system are affected by the environment in which it is , when this temperature is in extreme levels, and can cause effects such as: hyperthermia, dizziness, dehydration, headache, among others. The purpose of this research was to evaluate the quantitative effect that the symptoms of heat stress can cause on the productivity of operators in a foundry. Two normalizations were used to analyze the thermal stress: ISO 7243 (1989), which presents the methodology of the Index Wet Bulb Globe Temperature (WBGT) and ISO 7933 (2004), which presents the Required Sweat Rate method. After collecting environmental and personal data in six different points of the foundry, it was conducted analyzes of correlation and linear regression between the index of thermal stress and productivity to verify the relation between them. The results showed that productivity is inversely proportional to the level of heat stress, and that the index that has the best correlation with productivity is the WBGT, with a determination coefficient 94.05% , ie 94.05% of the variation found for the time of casting parts, productivity indicator is justified by the variation of WBGT index. The other indices had correlations of 82.16 % and 78.26%, and the linear regression provided in all methods determine an equation to predict productivity as a function of the variation of heat stress.