Systematic review and meta-analysis of cancer risks in relation to environmental waste incinerator emissions: meta-analysis of case-control and cohort studies

Abstract

Objectives: Various toxic substances can be generated from incinerators, and nearby residents can be exposed, and epidemiological studies have shown wide variations in risk estimates for cancer risk in populations living close to incinerators. Methods: According to the PRISMA guidelines, a literature search and systematic review were conducted to identify studies conducted on general populations exposed to environmental incinerator emissions and cancer outcomes. Meta-analysis was performed according to the cancer type, and two or more studies were reported. Subgroup analysis was done for sex, exposure estimation method, study period and type of outcome.Results: Eleven studies were found for qualitative review and meta-analysis. Seven studies had a case-control design, and four had a cohort design. The pooled effect size was not significant for breast, colorectal, liver, lung, lymphohematopoietic, NHL, sarcoma, stomach, bladder, CNS, larynx, leukemia and all-cancers. In the subgroup analysis, the pooled effect size of laryngeal cancer in females was 1.82 (95% Confidence Interval = 1.10–3.01), although only two studies were identified.Conclusions: So far, meta-analysis did not provide evidence of an increased risk for any cancer among populations living near waste incinerators except laryngeal cancer in female. However, since the number of reviewed literatures is small and there are various cancer types that have significantly increased in individual studies, regular evidence update is necessary.