Study result on the correlation between lead exposure and intellectual performance among children / Шинэ санаа Шинэ нээлт

ABSTRACT

Background@#Lead is known for their neurotoxicity and compared to adults, children are more vulnerable to lead exposure. Varieties of diseases are developed by lead induced damage in children, including decreased intelligent quotient and behavioral changes, such as anxiety. In normal condition lead does not exist in children’s blood and this toxic heavy metal enters into human body through respiratory way and accumulates in blood and bone to harm neurodegenerative and urinary systems. Therefore, the present study aimed to investigate whether the emitted lead from recycling factory for lead acid batteries, which is located in 9 km distance from Khonkhor town and 39 km faraway from Ulaanbaatar city with north-east direction, is affecting the intelligence of the local children.@*Methods@#There are 13 children involved in this study and the participants are divided into two groups, including subjects, who live in areas outside (n=10) and within (n=3) the 1000 m region of the factory zone. The blood sampling was collected according to WHO guidelines and lead level in blood was determined by Leadcare instruments at Environmental health and toxicological laboratory of National Center for Public Health. The intelligence analysis was conducted by Raven’s progressive matrices test. And the statistical analysis was performed by SPSS 21 software to assess correlation of blood lead levels and the intelligence among participated children. @*Results@#It is resulted that average lead level for children’s blood samples is 3.1±1.5 ug/dL and which is found beyond the acceptable range in WHO guidelines. The children’s intelligence was assessed by Raven’s colored Progressive Matrices analysis, which is practically accepted in China, which estimated that average intelligence score of participants were 48.3±13.2. According to correlation analysis of age, sex, intelligence and blood lead level, there was a weak positive correlation was found between children’s age and lead level in blood. In contrast, a weak reverse correlation was observed in regarding with sex and blood lead level and intelligence score was weakly reverse correlated with the lead level in children’s blood samples.@*Conclusions@#The determined average lead level was 3.1±1.5 ug/dL for blood samples collected from 13 children who involved in this study and the value is found under the WHO guidance value. Furthermore, their average intelligence score was estimated as 48.3±13.2. The comparative analysis shown that intelligence score of 3 children, who lives within 1000 m region of the recycling factory was lower than those who lives in outside region of the factory and have same age.