Lead is very toxic, and young children are at particular riskfor 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 associationsbetween low-level exposure to lead and children's performanceon intelligence tests at the ages of three to five years ina population that included many children whose blood lead concentrationsremained 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 electrothermalatomic absorption spectrometry. The following variables were used for the children were, thechild's sex, birth weight, and iron status and themother's IQ , years of education, race, tobacco use during pregnancy, yearly household income, and the total score for theHome Observation for Measurement of the Environment Inventory. Their IQ was measured by the Stanford–Binet Intelligence Scale and it was the dependentvariable.
Results
The mean blood lead concentration was lowest at the age of sixmonths 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 perdeciliter at five years. The lifetime average blood lead concentration was 7.7 µgper deciliter at the age of threeyears and 7.4 µg per deciliter at the age of five years. At three years of age, 86 childrenhad a peak blood lead concentration below 10µg per deciliter, as did 86, the ageof five years. The mean IQ was 90 for the participants at the age of three to five. The associations did not differsignificantly according to age. The estimatedoverall difference in IQ for each increase in the lifetime averagelead concentration of 1 µg per deciliter was –1.37points.
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 leadvalues in this sample, the estimated IQ loss was 4.6 pointsfor each increase in the blood lead concentration of 10 µgper deciliter. Their results are also consistent with findings from meta-analysesthat an increase in the blood lead concentration from 10 to30 µg per deciliter is associated with a decline in IQof 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 beenincrementally but consistently lowered over the past two decades. According to these scientists, they believe that every child with blood lead levels below 10 µgper deciliter should go through more intensive investigation. It is not only for intellectual problems, elevated lead concentration is alsoa 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 areadversely affected by environmental exposure to lead than previouslyestimated. Since there is no effective treatment for elevated blood lead, the least that we can do is help lower the causes.
