Premium
Multimedia persistence as an indicator of potential for population‐level intake of environmental contaminants
Author(s) -
MacLeod Matthew,
McKone Thomas E.
Publication year - 2004
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/03-390
Subject(s) - persistence (discontinuity) , population , environmental science , contamination , residence , bioaccumulation , residence time (fluid dynamics) , multiple exposure , statistics , environmental chemistry , computer science , ecology , environmental health , mathematics , chemistry , demography , biology , engineering , medicine , geotechnical engineering , sociology , computer vision
Although intuitively it is apparent that population‐level exposure to contaminants dispersed in the environment must be related to the persistence of the contaminant, there has been little effort to quantify this link formally. In this paper we investigate the relationship between overall persistence and/or overall residence time in a multimedia exposure environment and the population‐level intake of contaminants as expressed by intake fraction (iF), the cumulative fraction of chemical emitted to the environment that is taken up by members of the population. We demonstrate that for any given contaminant and emission scenario the definition of iF implies that it is directly proportional to the overall multimedia persistence ( P OV ), or the overall multimedia residence time ( T OV ). The proportionality constant has dimensions of time and represents the characteristic time for population intake (CTI) of the chemical from the environment. We then apply the CalTOX fate and exposure model to explore how T OV and CTI combine to determine the magnitude of iF. We find that CTI has a narrow range of possible values relative to T OV across multiple chemicals and emissions scenarios. We use data from the Canadian Environmental Protection Act Priority Substance List (PSL1) Assessments and multimedia P OV to show that exposure assessments based on empirical observation are consistent with interpretations from the model. Results indicate that P OV derived from screening‐level assessments of persistence, bioaccumulation potential, and toxicity (PBT) is a useful indicator of the potential for population‐level exposure.