Why is high persistence alone a major cause of concern?

Area of Science:

• Environmental Chemistry
• Chemical Regulation
• Risk Assessment

Background:

• Persistence is a key criterion in global chemical regulations.
• Highly persistent chemicals have historically caused significant pollution problems.
• Diverse chemical classes share unique challenges due to their persistence.

Purpose of the Study:

• To advocate for increased emphasis on chemical persistence in assessment and decision-making.
• To demonstrate the unique problems posed by highly persistent chemicals.
• To propose a regulatory framework prioritizing high persistence.

Main Methods:

• Case studies of chlorofluorocarbons, polychlorinated biphenyls, and per- and polyfluoroalkyl substances.
• Evaluative modeling calculations to simulate contamination trends.
• Analysis of the relationship between persistence, release, and environmental concentration.

Main Results:

• Continuous release of persistent chemicals leads to escalating environmental contamination regardless of other properties.
• Increasing concentrations correlate with higher probabilities of known and unknown adverse effects.
• Reversing contamination and effects from persistent chemicals can take centuries or longer.

Conclusions:

• High persistence alone should be sufficient grounds for chemical regulation (the "P-sufficient approach").
• This approach is not overly precautionary, given historical and ongoing issues.
• Regulating high persistence prevents poorly reversible future environmental impacts.