Exposure Load: Using biomonitoring data to quantify multi-chemical exposure burden in a population
Jeff B Willey1, Tyler Pollock1, Errol M Thomson2
1Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada.
International Journal of Hygiene and Environmental Health
|March 10, 2021
Summary
Canadians are exposed to many chemicals, with Exposure Load metric revealing most have 9-21 chemicals above detection limits. Smokers and older adults show higher multi-chemical exposures, highlighting potential health risks.
Area of Science:
- Environmental Health
- Toxicology
- Biomonitoring
Background:
- Concurrent exposure to multiple chemicals is common in the general population.
- Understanding the cumulative impact of these exposures is crucial for public health.
- Existing biomonitoring data offers a valuable resource for assessing multi-chemical exposures.
Purpose of the Study:
- To develop and apply a novel metric, Exposure Load, to quantify multi-chemical exposures in a population.
- To analyze Exposure Load distributions across different demographic groups using Canadian Health Measures Survey data.
- To identify population subgroups with disproportionately high multi-chemical exposures.
Main Methods:
- Utilized the 2012-2015 Canadian Health Measures Survey (CHMS) dataset.
- Calculated Exposure Load based on 44 biomarkers representing 26 chemicals across five concentration thresholds (LOD, 50th, 75th, 90th, 95th percentiles).
- Analyzed complete biomarker data for 1858 participants (aged 12-79 years) after multiple imputation.
Main Results:
- Canadians typically had an Exposure Load of 9-21 (out of 26) chemicals above the limit of detection (LOD).
- At higher thresholds (e.g., 95th percentile), most Canadians had 0-3 chemicals, but some had up to 15.
- Adolescents had lower Exposure Loads than adults; smokers had higher loads than non-smokers. No sex differences were observed.
Conclusions:
- Canadians are broadly exposed to numerous chemicals at low concentrations and fewer at high concentrations.
- The Exposure Load metric effectively identifies subpopulations with high cumulative chemical burdens.
- This approach can be applied to other datasets to advance understanding of multi-chemical exposures and their health implications.
Related Concept Videos
01:23Mechanistic Models: Compartment Models in Individual and Population Analysis
145
Mechanistic models are utilized in individual analysis using single-source data, but imperfections arise due to data collection errors, preventing perfect prediction of observed data. The mathematical equation involves known values (Xi), observed concentrations (Ci), measurement errors (εi), model parameters (ϕj), and the related function (ƒi) for i number of values. Different least-squares metrics quantify differences between predicted and observed values. The ordinary least...
145
01:25Strategies for Assessing and Addressing Confounding
217
Confounding is a critical issue in epidemiological studies, often leading to misleading conclusions about associations between exposures and outcomes. It occurs when the relationship between the exposure and the outcome is mixed with the effects of other factors that influence the outcome. Given that, addressing confounding is of high importance for drawing accurate inferences in research.
Confounding can be addressed at both the design phase of a study and through analytical methods after data...
Confounding can be addressed at both the design phase of a study and through analytical methods after data...
217
01:12Analysis of Population Pharmacokinetic Data
536
Analysis of population pharmacokinetic data involves studying the behavior of drugs within diverse populations to understand their pharmacokinetic parameters. Traditional pharmacokinetic methods typically involve collecting samples from a few individuals and estimating these parameters. While these methods are commonly used, they have limitations in capturing the variability in drug response among individuals or heterogeneous populations. Population pharmacokinetics is employed to address these...
536
01:23Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
258
Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy.
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
258
01:23Drug Concentrations: Measurements
808
Drug concentration is the quantity of a drug present in a biological sample. Measuring drug amounts in biological samples allows the clinician to understand how a drug is absorbed, distributed, metabolized, and excreted. Samples can be obtained through invasive or non-invasive methods. Invasive techniques involve surgical or parenteral interventions to gather blood, cerebrospinal fluid, or tissue biopsy. Conversely, non-invasive approaches provide samples like urine, feces, and saliva.
Plasma...
Plasma...
808
01:11Bioavailability Study Design: Single Versus Multiple Dose Studies
76
Bioavailability studies are essential for understanding how a drug is absorbed, distributed, metabolized, and excreted in the body. These studies assess the extent and rate at which the active pharmaceutical agent becomes available at the site of action. The design of bioavailability studies can involve single-dose or multiple-dose regimens, each with distinct advantages and limitations.Single-dose studies are the preferred approach due to their simplicity and reduced drug exposure for...
76