Mean Blood Lead Level in Iranian Workers: A Systematic and Meta-Analysis

Abstract

Context: Exposure to lead is a global health issue. Several studies have demonstrated the harmful and irreparable effects of this heavy metal on human. Workers in lead-related industries are more exposed to lead than other people are. Therefore, the present study was conducted to assess the mean blood lead level (BLL) in Iranian workers through meta-analysis technique. Evidence Acquisition: The present study was conducted based on PRISMA guidelines for systematic review and meta-analysis studies. We searched national and international online databases such as Magiran, SID, Medlib, Iranmedex, Scopus, Embase, Science Direct, PubMed, Web of Science, and Google Scholar search engine using Mesh keywords up to 2017. Heterogeneity among studies was check using Q test and I-2 index. Data pooled using random effects model. Results: In 31 studies including 2767 Iranian workers, the mean BLL was estimated to be 43.1 mu g/dl (95 CI Confidence Interval: 35.19-50.83). The lowest and highest BLL was estimated in the west of Iran (28.34 mu g/dl 95% CI: 17.31-39.37) and center of Iran (46.32 mu g/dl 95% CI: 36.73-55.91), respectively. Regarding job-specific BLL, the lowest and highest BLL was estimated in textile industry workers (12.33 mu g/dl 95% CI: 0-26.76) and lead-zinc mines workers (72.58 mu g/dl 95% CI: 26.06-119.10), respectively. Mean BLL based on province was studied and the lowest level was estimated in Isfahan province (29.79 mu g/dl 95% CI: 0-73.31) and the highest level was estimated in Markazi province (96.47 mu g/dl 95% CI: 88.61-104.33). The relationship between mean BLL in Iranian workers, year of study (P = 0.46) and mean work experience (P = 0.15) was not significant. Conclusions: Due to high BLL in Iranian workers in lead-related industries, it is necessary to increase frequent screening and protective activities and perform scheduled clinical and paraclinical examinations in workers.