Exposição mercurial: perfil clínico-epidemiológico de mulheres na região do Baixo Tapajós

Abstract

Mercury is a heavy metal that causes harm to human health. Mercury exposure occurs through means such as the burning of amalgam and the consumption of mercury-contaminated fish. Women of childbearing age are part of the vulnerable group and must be monitored; in order, above all, to avoid the harmful health effects of mercury exposure. Even more so when considering that the effects of mercury exposure affect the fetus in the intrauterine period, contributing to delays and/or damage to the nervous system, congenital malformations and abortions. In the Brazilian Amazon, there is an interest in investigating mercury exposure, given the anthropic mining activities in the region, as well as the presence of contaminated fish that add risks to the health of the population, mainly due to the high consumption of fish by people from the Amazon region. Understanding that in the Baixo Tapajós region there is an environmentally exposed population and in view of the dangers that mercury exposure may have in women, this study aims to characterize the epidemiological and clinical profile of women environmentally exposed to mercury in the Baixo Tapajós region, Pará. This is a descriptive, cross-sectional and quantitative study, which was carried out based on data collected from 2015 to 2019. The population sample of the present study is 327 women, living in urban, riverside and plateau areas of the region of Lower Tapajos. For the purposes of the research, social, demographic, food, anthropometric, clinical and laboratory variables were collected and analyzed. An analysis of the concentration of mercury in the blood was also performed, considering as “exposed” women with more than 10 μg/L of mercury. Descriptive and inferential statistical analysis of these variables was performed using the STATA software (version 16). Based on the proposed data analysis, the results showed that 73.4% (n=240) of the women had mercury levels above 10 μg/L, of these 81.1% had basic schooling and were engaged in occupational activities related to fishing (93 .1%) and agriculture (88.6%). Among these exposed women, 70.5% (n=155) were of childbearing age, however, women over 50 years old were the participants with the highest mean blood mercury value of 41.4±51.3 μg/L and median of 21.2 μg/L. It was shown that 60.4% (n=145), that is, more than half of the women, lived in river areas and were exposed to high levels of mercury. Regarding the symptoms, those related to the nervous and muscular systems were more frequent, it is noteworthy that the frequency of symptoms was three times higher among women exposed to high levels of mercury. The anthropometric evaluation showed a predominance of 56.9% (n=124) of overweight/obese women, of which 79% (n=98) had mercury levels above 10 μg/L, with an average value of 46 .6±59.6 μg/L. Regarding blood pressure, 49.3% (n=100) of the women had blood pressure levels ≥140x90mmHg, of these 82% (n=82) had mercury values above 10 μg/L. It is noteworthy that the proportion of overweight/obese women was more than three times higher among women with high mercury levels, as well as altered blood pressure, which was 4.5 times more frequent in the subgroup of exposed women. The results of the present research demonstrate a profile of high mercury exposure in women of childbearing age, still portraying the strong influence of factors linked to social vulnerability, geographic isolation and high consumption of fish for the exposure of women to mercury. The results also point to the presence of evidence of the negative effects of mercury exposure on women's health, which encourages the development of more studies aimed at measuring them. In view of this health scenario, actions must be planned for the intervention and control of mercury exposure of the population in the Amazon, for which what must be considered is the complex relationship established between the population and the environment. The social and economic profile of this population follows the influence of the countryside, forest and water, so solutions that aim to curb the consumption of fish tend to be impractical, even more so because they disregard the social vulnerability of this population. In order to successfully control and monitor mercury, appropriate strategies must be devised for the specificities of the territory and the population. To this end, popular participation and empowerment on issues involving mercury, health and the environment are fundamental to the success of this process, with access to information being the first step.