Working in cold environments: case study with environmental and electrocardiographic monitoring

Abstract

Background - In low-temperature working environments, physiological reactions aimed at adjusting thermal balance occur, leading sometimes to cardiovascular overload. However, the cold is often a key factor in the production, processing and packaging of products, especially in the food industry, which makes occupational exposure to a cold environment a reality. This study’s main aim is to study the work conditions and to identify electrocardiographic alterations in individuals working in a meat processing center (MPC), facing low temperatures (<8ºC). Methods - Environmental parameters as temperature, relative humidity, air velocity were measured through specific equipment. Itwas calculated the index IREQ (required clothing insulation), the characterization of basic clothing insulation and the metabolic activity per job. Electrocardiographic monitoring was obtained through Holter’s ambulatory electrocardiography. Relevant information was also collected through a Holter’s diary, a questionnaire and a digital thermometer. Results/Discussion - The sample is subject to a slight degree of hypothermia which can be due to the fact that no evidence of thermal stress was found and to the confluence of factors such as: the large amount of workers that wears additional clothing besides the working clothes provided by the MPC, and the high metabolic rate inferred by the analysis of the cardiac frequency. The results of the study are different from those found in the bibliography used – in this study’s sample no electrocardiographic expression of hypothermia has been observed. Conclusion - In order to improve working conditions, some corrective organizational measures can be implemented, since the control of the thermal environment is not feasible. Although there are not electrocardiographic alterations it is important to include cardiovascular exams in periodical medical examinations (in addition to the electrocardiogram, should also perform an Holter ambulatory electrocardiogram, 24 hours blood pressure monitorization and echocardiogram) since working in cold environments can cause cardiac changes likely to come up or aggravate due to prolonged exposure.

Keywords

• exposição laboral ao frio, monitorização ambiental, alterações electrocardiográficas, electrocardiografia ambulatória de Holter, hipotermia, onda J