The limited nature of evidence on some environmental cancer hazards should not be confused with proof that no harm has occurred: the research is hard to do, and, in the US, very little of it is now funded by the government and private sector. Moreover, confusion about environmental cancer risks also results from longstanding, carefully cultivated, and well-financed disinformation campaigns inspired by the machinations of the tobacco industry.
对某些环境性癌症隐患的证据有限不应该与证明无害混为一谈：相关研究比较困难，且在美国只有极少一部分受到政府和商业的资助。另外，烟草工业通过诡计，以巨额的资金支持发动长期的、处心积虑的假信息攻势，也在环境癌症风险方面混淆视听。