Module 2 : Contaminants and pathways into atmosphere

Lecture 4 : Organic Pollutants

Organic biocides

Fate of biocides in the environment:

–Chemical stability (rate it degrades to other compounds)

–Mobility (mechanism and rate of transport)

Rapid degradation mobility less of an issue

Different degradation mechanisms may operate as the pesticide moves to a new environment

Degradation products may have biocidal properties:

–Usually reduced toxicity, but sometimes toxicity is enhanced

Polychlorinated Hydrocarbons

All the Dirty Dozen are polychlorinated hydrocarbons

They are stable and do not readily degrade to less toxic forms

–Persist in the environment for a long time and can bioaccumulate through the food chains

Insoluble in water, soluble in fats

Polychlorinated hydrocarbons of particular concern are: