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202 Gupta et al. | Journal of Clinical and Translational Research 2024; 10(3): 201-208
sources that significantly contribute to lead exposure: gasoline was approximately 30 km from the All India Institute of Medical
additives; food can solder; lead-based paints; ceramic glazes; Sciences (AIIMS), Mangalagiri. The study was conducted in 2022
drinking water systems; and cosmetic and folk remedies [2]. among adult males and females from 20 to 60 years of age. The
Other significant exposures include inadequately controlled study participants were divided accordingly into three groups:
industrial emissions from lead smelters and battery recycling (i) Group 1: Direct occupationally exposed individuals, such
plants, contaminating both the environment and people in the as workers in lead battery manufacturing, construction
vicinity [2]. The highest level of environmental contamination workers, demolition workers, gas station attendants, lead
is found to be associated with uncontrolled recycling operations, smelters, smolderers, and painters.
with the most highly exposed adults being those who work with (ii) Group 2: Indirect air pollution-exposed individuals, such as
lead [3]. traffic police, police, truck drivers, bus drivers, auto drivers,
In India and most developing countries, the main source of and petrol bunk workers.
lead pollution was previously automobile exhaust. With the use (iii) Group 3: Indirect non-occupationally exposed individuals,
of unleaded petrol, lead pollution due to automobile exhaust such as indoor officer workers, teachers, primary health-
has drastically dropped [4]. Approximately 143,000 people die care workers, and housewives.
annually from lead poisoning, accounting for 0.6% of the global
disease burden [5], and Southeast Asia accounts for over half of Individuals were eligible for participation in Groups 1 and
the global burden of lead-related illness. Greater blood lead levels 2 after working in the same occupation for at least 6 months
(BLL) are linked to increased all-cause mortality in both men and or in Group 3 after residing in the area or working in the same
women with cardiovascular diseases. Although the World Health occupation for the past 6 months. Individuals with symptoms
Organization (WHO) has set a standard BLL of 5 µg/dL for suggestive of critical illness, diabetes mellitus, hypertension,
adults [1], the Environmental Health Committee of the Council recently underwent surgery, and those who denied consent were
of State and Territorial Epidemiologists (CSTE) indicated that a excluded from the study.
blood lead reference value (BLRV) >3.5 µg/dL is considered high. The sample size was calculated using the sample formula
BLRV is used to identify patients with the highest BLL in the required per group:
population but is not indicative of a toxicity threshold [6]. Adult [Z + Z ] 2
lead toxicity is typically considered at mean BLL ≥10 µg/dL, but n (σ = 1 2 σ + 2 2 ) × 1 @/2− 1− β (I)
there is evidence linking long-term risks to chronic lead exposure (M − M ) 2
1
2
below 10 µg/dL [7]. Other studies indicate a correlation between
higher BLLs and increased cardiovascular mortality in adults [8]. Where σ denotes the standard deviation (SD) of the outcome
1
Lead is a strong inhibitor of δ-aminolevulinic acid dehydratase, variable in Group 1 σ denotes the SD of the outcome variable
2
,
affecting the spleen and hematopoietic system [9]. in Group 2, Z 1-@/2 and Z denote the probability of two types
1-β
According to evidence on the long-term effects of low- of errors at 1.96 and 1.282, respectively, and M M denotes
2
1 -
level lead exposures and the prevalence of lower levels in the the mean difference between groups The means of continuous
.
population, the United States (US) Department of Health and variables were compared using a t-test. We utilized the findings
Human Services advises reducing BLLs among all individuals from two previous studies as Groups 1 and 2 to determine the
to <10 µg/dL [7,10,11]. It is widely recognized that the lead sample size. Group 1 included workers handling raw material
exposure standard set by the US Occupational Health and in a battery factory in Nellore, Andhra Pradesh, with a mean
Safety Administration is outdated and does not provide adequate ± 2SD BLL (µg/dL) of 26.2 ± 2.142 in 2016 – 2017 [3].
protection against lead poisoning [10,12]. This standard permits Group 2 included non-occupationally lead-exposed healthy
workers to continue working in lead-exposed environments school teachers from various public and government sectors,
with BLLs of up to 40 µg/dL. representing various nodal areas of Jodhpur with a mean ± 2SD
Developed countries, such as the US, United Kingdom, and BLL (µg/dL) of 6.89 ± 9.5 [13]. Utilizing a 95% confidence
Germany, have implemented aggressive measures to address interval (CI) and 90% power, we calculated the required sample
lead poisoning while developing countries present slower and size to detect a 3.0 µg/dL difference in BLLs in any two groups
more sporadic actions. Within the past decade, there have been to be 60. Hence, the total sample studied was 180, excluding
numerous reports of lead poisoning in humans, particularly from nonresponse and attrition.
developing countries faced with environmental and occupational After ascertaining the eligibility of the participant, detailed
lead exposure [4]. The present study was conducted to estimate information about the study was provided through the Participant
and compare BLLs in the adult population with and without Information Sheet and consent document. Both these documents
occupational lead exposure. were in Telugu, and any difficult words were explained with the
assistance of a local interpreter. Data collection was conducted
2. Methods once written consent was accorded. The project was approved

2.1. Study design by the ethical committee of the AIIMS Institute (AIIMS/MG/
IEC/2022-2023/135).
A baseline survey of the prospective cohort study was Investigators were trained in data collection, blood collection,
conducted in the Guntur district, Andhra Pradesh, India, which and transportation. A pilot survey was conducted and corrective

DOI: https://doi.org/10.36922/jctr.23.00130