乌普萨拉大学的Lars Lind和Monica Lind教授以及厄勒布鲁大学的环境化学家对乌普萨拉1000名随机选择的70岁老人进行了一项调查，发现多氯联苯的高血液水平与过早死亡的风险之间存在相关性。
Professors Lars Lind and Monica Lind at Uppsala University and environmental chemists at Örebro University conducted a survey of 1000 randomly selected 70 year olds in Uppsala and found the link between high blood level of PCBs and risk of premature death.
PCBs had been used as a flame-retardant. Its toxicity has prompted many countries to ban these chemicals many years ago. But these toxic chemicals are persistent and can still be found in the polluted environment today.
For the study, the researchers followed the subjects for more than 10 years and found that those with high blood PCBs were 50% more likely to die than those with lower PCBs in their blood.
Early studies have linked high PCB levels to atherosclerosis in humans and experiment animals.
Because of the toxicity of PCBs, another group of chemicals polybrominated biphenyls which are similar to PCBs are used as flame-retardants. Critics point out that these replacements can be as toxic as PCBs because they are chemically similar.
PCBs are fat soluble. They can be found at high levels in fatty foods such as fish (herring and salmon in polluted areas), meat and dairy products. Plant-derived foods have much lower of these toxic chemicals. (Dr. Lu)