Lead Exposure Assessment among Pregnant Women, Newborns, and Children: Case Study from Karachi, Pakistan

Abstract

Lead (Pb) in petrol has been banned in developed countries. Despite the control of Pb in petrol since 2001, high levels were reported in the blood of pregnant women and children in Pakistan. However, the identification of sources of Pb has been elusive due to its pervasiveness. In this study, we assessed the lead intake of pregnant women and one- to three-year-old children from food, water, house dust, respirable dust, and soil. In addition, we completed the fingerprinting of the Pb isotopic ratios (LIR) of petrol and secondary sources (food, house-dust, respirable dust, soil, surma (eye cosmetics)) of exposure within the blood of pregnant women, newborns, and children. Eight families, with high (~50 μg/dL), medium (~20 μg/dL), and low blood levels (~10 μg/dL), were selected from 60 families. The main sources of exposure to lead for children were food and house-dust, and those for pregnant women were soil, respirable dust, and food. LIR was determined by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) with a two sigma uncertainty of ±0.03%. The LIR of mothers and newborns was similar. In contrast, surma, and to a larger extent petrol, exhibited a negligible contribution to both the child’s and mother’s blood Pb. Household wet-mopping could be effective in reducing Pb exposure. This intake assessment could be replicated for other developing countries to identify sources of lead and the burden of lead exposure in the population.

Long range correlations of the ion current in SV channels. Met3PbCl influence study

“…The accepted consensus is that any level of lead is unhealthy [14]. In developing countries, pregnant women and children are still commonly experiencing today the lead concentration in blood in the range 100-500 μg/L when values <50μg/L are desirable [15]. An important source of lead for humans are plants as the food ingredient [16].…”

An experimental study of arsenic and lead concentration in common food sources

“…In the previous study, the weekly As intake of young children through food was high (188 µg/kg bw) and around 14% of the children's weekly As intake was exceeding the provisional tolerable weekly intake (PTWI) level of 15 µg/kg bw. 18,19 The logical next step was to identify the main sources of food commonly contributing to high level of exposure among the vulnerable population. This study confirms that the common food items consumed by the population including lentils, potato and chicken were contaminated with As and Pb in the city of Karachi, Pakistan.…”

“…have reported high blood lead levels in Pakistan. 17,18 However, the sources of exposure to Pb are unclear.…”

“…This experiment was part of investigation of our recently published work to estimate the exposure of As and Pb among pregnant women, children and newborn in Pakistan. 18 The common food items including lentils, potato and chicken were analyzed for concentration of As and Pb. Furthermore, this investigation estimated the contribution of these metals from leaching during cooking process using commonly used cooking utensils.…”

The Metal Neurotoxins: An Important Role in Current Human Neural Epidemics?

“…It now reports, 45 years later, that early exposure does have long-term ramifications [ 68 ]. Additionally, regrettably, in cities such as Karachi, Pakistan, pregnant women, newborns, and children are still commonly experiencing blood values today in the range 100–500 µg/L when values <50 µg/L are desirable [ 69 ]. Due to lead’s continued presence in many locations, only temporary MRL values currently tend to be in use, mainly as a coarse measuring indicator for doctors, and are gradually being lowered as it becomes possible with environmental improvements.…”