Paris-Saclay University, UVSQ, Inserm, Gustave Roussy, "Exposome and Heredity" Team, CESP UMR1018, F-94805 Villejuif, France.
Paris-Saclay University, UVSQ, Inserm, Gustave Roussy, "Exposome and Heredity" Team, CESP UMR1018, F-94805 Villejuif, France.
Environ Int. 2021 Sep;154:106663. doi: 10.1016/j.envint.2021.106663. Epub 2021 May 31.
Polychlorinated biphenyls (PCBs) are a large family of man-made organic, ubiquitous, and persistent contaminants with endocrine-disrupting properties. PCBs have been associated with numerous adverse health effects and were classified as carcinogenic to humans, but their long-term impact on mortality risk in the general population is unknown.
To conduct a systematic review and meta-analysis in order to assess whether background exposure levels of PCBs increase all-cause and cancer- and cardiovascular-specific mortality risk in the general population.
We searched the Pubmed, Web of Science, Cochrane Library, and Embase databases for eligible studies up to 1st of January, 2021. We included cohort and nested-case control studies comparing the lowest vs. the highest background exposure level of PCBs in the general population and reporting data for all-cause mortality and/or cancer-/cardiovascular-specific mortality. Studies reporting occupational and accidental exposures were excluded. Random-effects meta-analysis was used to estimate summary relative risks (SRRs) and 95% confidence intervals (CIs). Heterogeneity across studies was assessed by I2 statistics, and publication bias both graphically and using Egger's and Begg's tests. Quality of included studies was assessed using the National Toxicology Program/Office of Health Assessment and Translation (NTP/OHAT). Confidence in the body of evidence and related level of evidence were assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) based on the NTP/OHAT framework. The protocol was registered in PROSPERO (CRD42020178079).
The initial search led to 2,132 articles. Eight prospective cohort studies met our inclusion criteria, leading to 72,852 participants including 17,805 deaths. Overall exposure to PCBs was not statistically significantly associated with all-cause mortality (SRR = 1.13, 95% CI = 0.90-1.41, n = 7 studies, low certainty); however, dietary exposure to PCBs was associated with an increased risk of cardiovascular-specific mortality (SRR = 1.38, 95% CI = 1.14-1.66, n = 3 studies, moderate certainty), while no association was found with cancer-specific mortality (SRR = 1.07, 95% CI = 0.72-1.59, n = 5 studies, low certainty).
Our meta-analysis suggests that background exposure to PCBs is associated with an increased risk of cardiovascular-specific mortality in the general population with a "moderate" level of evidence. These findings should be interpreted with caution given the small number of studies on mortality in the general population.
多氯联苯（PCBs）是一种人造的、普遍存在且持久的有机污染物，具有内分泌干扰特性。PCBs 与许多不良健康影响有关，并被归类为人类致癌物质，但它们对一般人群死亡率风险的长期影响尚不清楚。
进行系统评价和荟萃分析，以评估一般人群中 PCB 的背景暴露水平是否会增加全因死亡率以及癌症和心血管疾病特异性死亡率。
我们在 Pubmed、Web of Science、Cochrane 图书馆和 Embase 数据库中检索了截至 2021 年 1 月 1 日的合格研究。我们纳入了比较一般人群中 PCB 的最低 vs. 最高背景暴露水平的队列研究和嵌套病例对照研究，并报告了全因死亡率和/或癌症/心血管疾病特异性死亡率的数据。排除了报告职业和意外暴露的研究。使用随机效应荟萃分析来估计汇总相对风险 (SRR) 和 95%置信区间 (CI)。通过 I2 统计量评估研究之间的异质性，并使用 Egger 和 Begg 检验进行图形和出版偏倚评估。使用国家毒理学计划/健康评估和转化办公室 (NTP/OHAT) 评估纳入研究的质量。使用基于 NTP/OHAT 框架的推荐评估、制定和评估 (GRADE) 来评估证据体的可信度和相关证据水平。该方案在 PROSPERO（CRD42020178079）中进行了注册。
最初的搜索导致了 2132 篇文章。八项前瞻性队列研究符合我们的纳入标准，共纳入 72852 名参与者，其中 17805 人死亡。总体 PCB 暴露与全因死亡率无统计学显著相关性（SRR=1.13，95%CI=0.90-1.41，n=7 项研究，低确定性）；然而，饮食中 PCB 的暴露与心血管疾病特异性死亡率的增加相关（SRR=1.38，95%CI=1.14-1.66，n=3 项研究，中等确定性），而与癌症特异性死亡率无关（SRR=1.07，95%CI=0.72-1.59，n=5 项研究，低确定性）。
我们的荟萃分析表明，一般人群中 PCB 的背景暴露与心血管疾病特异性死亡率的增加相关，证据水平为“中等”。鉴于一般人群死亡率的研究数量较少，这些发现的解释应谨慎。
