Most often used in regard to the natural environment, the term pollute means to make foul or unclean, degrade ecological and/or human health, contaminate or defile, and, in a religious sense, render ceremonially impure or desecrate. The verb pollute derives from the Middle English polute, and this from the Latin pollūt(us), the past participle of polluere, which meant to soil, defile. Pollution generally denotes an undesirable condition, where there is too much of something (the pollutant or contaminant) in a natural or other beneficial system. It is, then, not an objectively determined state of affairs. Rather decisions about pollution require both science (for example, identification, monitoring, and classification) and ethics and politics (such as debate about what is undesirable, what is acceptable, who should monitor pollutants, and who should be held accountable). Although pollution is, in a sense, an unavoidable byproduct of human (and nonhuman...