Effects of the Decrease in Blood Lead Levels on Renal and Neurological Functions Among Occupationally Exposed and Unexposed Populations of South India: A Cohort Study.

Introduction: Exposure to lead in excess of the permissible limit is a known risk factor leading to preventable morbidity. The present study aimed to assess whether there is a change in the neurological and renal parameters among adults with blood lead levels (BLLs) higher than recommended at baseline and after prevention among differently exposed adults.

Methodology: In the Guntur District of Andhra Pradesh, India, a cohort study was carried out in 2022-2023 among 180 adult males and females aged 20 to 60 years in three groups: direct occupational exposure, indirect occupational exposure, and no occupational exposure. If the blood levels were more than or equal to 5 mcg/dL, the participant's detailed neurological examination was done at baseline and end of follow-up. During the six-month follow-up period, health education on lead awareness was given monthly. BLLs were estimated using graphite furnace atomic absorption spectrometry (GFAAS). Serum creatinine was estimated using Jaffe's modified method. On neurological examination, reflexes, power, and sensation were assessed. The vibration perception threshold was determined using a biothesiometer. A p-value less than 0.05 was considered to be statistically significant.

Results: Among the 180 participants, the mean BLLs at baseline were 7.15±3.06 mcg/dL. The findings revealed a statistically significant decrease in mean BLLs at baseline to end of six-month follow-up. Despite this improvement, participants with BLLs ≥5 mcg/dL still accounted for a considerable proportion, albeit reduced, particularly in Groups 1 and 2. There were no statistically significant changes observed in the proportions of participants with abnormal serum creatinine, anemia, or abnormal neurological parameters.

Conclusion: These results suggest that while prevention activities may effectively reduce overall BLLs, there might be challenges in completely mitigating the impact on certain health parameters, such as renal and neurological functions.