Exposição ao mercúrio em crianças com transtorno do espectro do autismo no município de Santarém, Pará.

Abstract

This study aimed to investigate the relationship between exposure to Hg and Autism Spectrum Disorder in the city of Santarém, Pará. 23 mothers and 25 children diagnosed with ASD assisted by Association of Parents and Friends of Exceptionals (APAE) and ‘Casa azul’ participated in the study. The analysis of total Hg was performed through the blood of these children as well as their mothers to investigate possible sources of exposure and accumulation of Hg, besides other topics related to the pre, peri and postnatal period capable to interfere with the diagnosis of ASD it was also applied a semi-structured interview to the mothers. The Childhood Autism Rating Scale (CARS) was applied to assess the profile and levels of autism (mild or moderate and severe). In the descriptive analysis, it was observed that 95% of the children were male, 56% of them were in the non-autistic range according to the CARS classification, 68% had low fish consumption and 52% were classified as exposed, it means with levels of Hg above 10 µg / L. In the inferential analysis, normality was first verified through the Shapiro-Wilk test. Frequency distribution and association analysis were performed using the Chi-square test of adherence and contingency (rows x columns), which showed a statistically significant difference between the classification of exposed and unexposed mothers (p = 0.0371), gender of the children (p <0.0001) and the classification regarding the level of ASD (p = 0.0424). The Mann-Whitney test was used to compare the medians. To evaluate the relationship between age and frequency of fish consumption with levels of Hg, the Spearman correlation test was applied. In both tests, a significance level of 5% was used. The tests were performed in the BioEstat program. It was observed that there was no association or positive correlation between the variables: age, gender, frequency of fish consumption with medication use of children with level of Hg in the blood, showing that even with the low frequency of fish consumption, children presented high levels of Hg and these high levels do not have a linear and positive correlation with the degree of ASD. Thus, it is concluded that there is a need for further studies involving this theme in order to better clarify the relationship between Hg and ASD, especially regarding the action on the child's nervous and immune systems and its relationship to genetic mechanisms.