Intellectual Impairment in Children with Blood Lead Concentrations Below 10 µg Per Deciliter

Lead is very toxic, and young children are at particular risk for exposure. A lot of studies show that blood lead levels above 10 µg can lead to intellectual damage. This is why any level which is above 10 µg is marked as “level of concern”. Most studies show that the average is below 10 µg, but there are still areas where the average is much higher. This study examines associations between low-level exposure to lead and children’s performance on intelligence tests at the ages of three to five years in a population that included many children whose blood lead concentrations remained below 10 µg per deciliter.

Hypothesis

Scientist believe that the as the concentration is declining, the IQ will be greater. They believe that the lead exposure has a negative effect on children intellectual tests.

Methodology

This study experiments, there were 198 participants that had met the standards. Their blood lead level was measured and also, the participants had to take intellectual tests to ensure maximum results. Blood lead concentrations were determined by electrothermal atomic absorption spectrometry. The following variables were used for the children were, the child’s sex, birth weight, and iron status and the mother’s IQ , years of education, race, tobacco use during pregnancy, yearly household income, and the total score for the Home Observation for Measurement of the Environment Inventory. Their IQ was measured by the Stanford–Binet Intelligence Scale and it was the dependent variable.

Results

The mean blood lead concentration was lowest at the age of six months which was 3.4 µg per deciliter. The concentration was maximal at two years, 9.7 µg per deciliter. After the maximal at two years of age, the blood lead level was then decreased to 6.0 µg per deciliter at five years. The lifetime average blood lead concentration was 7.7 µg per deciliter at the age of three years and 7.4 µg per deciliter at the age of five years. At three years of age, 86 children had a peak blood lead concentration below 10 µg per deciliter, as did 86, the age of five years. The mean IQ was 90 for the participants at the age of three to five. The associations did not differ significantly according to age. The estimated overall difference in IQ for each increase in the lifetime average lead concentration of 1 µg per deciliter was –1.37 points.

Discussion

Because of this study, there is more accurate information and more answers to why children IQ keep decreasing as the blood lead level increases. In the linear model involving the full range of lead values in this sample, the estimated IQ loss was 4.6 points for each increase in the blood lead concentration of 10 µg per deciliter. Their results are also consistent with findings from meta-analyses that an increase in the blood lead concentration from 10 to 30 µg per deciliter is associated with a decline in IQ of 2 to 6 points. This shows that the for every time the blood lead level increases by 10 µg per deciliter, there is will be a IQ decline for 2.

Conclusion

In conclusion, the scientist hypothesis was correct. Blood lead levels had a negative affect on children IQ average. It is said that the definition of an elevated blood lead concentration has been incrementally but consistently lowered over the past two decades. According to these scientists, they believe that every child with blood lead levels below 10 µg per deciliter should go through more intensive investigation. It is not only for intellectual problems, elevated lead concentration is also a risk factor for other public health problems, including delinquency, cardiovascular disease, renal disease, and dental caries. Our findings suggest that considerably more U.S. children are adversely affected by environmental exposure to lead than previously estimated. Since there is no effective treatment for elevated blood lead, the least that we can do is help lower the causes.