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Updated: Aug 14, 2026
Measurement of Chitinase Activity in Biological Samples
Published on: August 22, 2019
A dried blood spot method to evaluate cholinesterase activity in young children
Elizabeth D Hilborn1, Stephanie Padilla
1National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA. hilborn.e@epa.gov
Insights
A pilot study found that dried blood samples can effectively monitor organophosphate pesticide exposure in young children. This method shows significant correlation with whole blood cholinesterase activity, aiding field studies.
Area of Science:
- Environmental Health
- Pediatric Toxicology
- Biomonitoring
Background:
- Organophosphate pesticide exposure is a concern for young children, particularly in agricultural areas.
- Reliable field methods are needed to detect and monitor this exposure in pediatric populations.
- Cholinesterase activity in blood is a key biomarker for organophosphate exposure.
Purpose of the Study:
- To evaluate the feasibility of using dried blood samples for monitoring cholinesterase activity in young children.
- To assess the correlation between cholinesterase activity in dried blood versus whole blood samples.
- To determine the utility of a dried blood method for field-based pesticide exposure studies in children.
Main Methods:
- A pilot study involved 20 children (11-18 months) from a US/Mexico border agricultural community.
- Venous blood samples were collected twice, 4 weeks apart.
- Cholinesterase activity was measured in both whole heparinized blood and blood dried on filter paper.
Main Results:
- Cholinesterase activity was consistently lower in dried blood samples compared to heparinized whole blood.
- A significant positive correlation (Spearman r = 0.6, p = 0.01) was observed between cholinesterase activity in dried and whole blood.
- The dried blood method demonstrated reliability for tracking changes over time.
Conclusions:
- Dried blood samples offer a viable field method for assessing organophosphate pesticide exposure in young children.
- This method provides a practical alternative for biomonitoring cholinesterase activity in pediatric populations during field studies.
- The correlation suggests dried blood is a useful matrix for evaluating changes in cholinesterase values over time.
Abstract:
Field methods are needed to detect and monitor the organophosphate pesticide exposure of young children. Twenty children, aged 11 to 18 mo, living in an agricultural community along the United States/Mexico border were enrolled in a pilot study investigating methods to detect pesticide exposure. Healthy children were recruited at pediatric clinics with the informed consent of their parents. Venous blood samples were collected from children twice, 4 wk apart. Cholinesterase activity was compared in whole heparinized venous blood with venous blood samples dried on filter paper. Although the amount of activity in the dried blood was consistently less than in the heparinized blood, the activity was significantly correlated: Spearman r = .6 (p = 0.01). This dried blood method may be used during field studies to evaluate changes in cholinesterase values in children over time.
