GRF 2nd One Health Summit 2013: Presentation by Juthasiri Rohitrattana, College of Public Health Sciences, Chulalongkorn University, Thailand

1. Relationship between children’s environment and
organophosphate pesticide exposures among
children living in agricultural area, Thailand
Rohitrattana Juthasiri, Siriwong Wattasit, Tunsaringkarn Tanasorn,
Robson G. Mark, Fiedler Nancy
Presented by Ms.Juthasiri Rohitrattana, M.Sc.
College of Public Health Sciences, Chulalongkorn University, Thailand

2. Rationale



Pesticide use for agricultural purposes is rising in Thailand.
Organophosphate (OP) insecticide is one of the most
popular agents used for crop protection and known as
nervous system toxicants or cholinesterase inhibitor.
Chlorpyrifos is the most popularly used in rice fields in
Pathum Thani Province, Central Thailand.

3. Rationale



OP exposure has been associated with delays in mental
development, behavioral problems and poor short-term
memory and motor skill.
In Thailand, farms and residential areas are not totally
separated.
Child who lives near the agricultural area can be exposed
to the pesticides via their environment and daily activities.

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6. Objectives
To compare the pesticide exposure between
children living in rice area and in aquaculture area.
 To determine the relationship between children’s
environment and activities with pesticide exposure
among children living in agricultural areas

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7. Methodology



Research design: cross-sectional study
Study population:
- Healthy children aged 6 to 8 years old (N = 53)
- 24 children from rice area (high OP application
area) in Khlong Luang District, Pathum Thani Province,
Thailand.
- 29 children from aquaculture area in Lum Luk Ka
District, Pathum Thani Province, Thailand.
Data collection: October 2011

8. Rice farming area

9. Aquacultural area

10. Measurement tools
 Questionnaires
– Face-to-face interview with the
participant’s parents about their child’s activities
and environments.
 Urine samples - First morning void urine
samples were analysed for the OP class-specific
metabolites (diakylphosphate; DAPs).
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11. Results
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12. Children’s environmental conditions.
Characteristics
Study area
Aquaculture area
Rice area
(n=24)
Rice farmer family
n
24
Significance
(χ2 test)
(n=29)
%
100
n
0
%
0
Proximity to rice farm:
p
<0.001
<0.001
≤500 m.
24
100
10
34.5
>500 m.
0
0
19
65.5
Frequency of floor cleaning:
0.29
Not everyday
6
25.0
4
13.8
Everyday
18
75.0
25
86.2
Frequency of OPs usage on farm:
<0.001
Never
1
4
29
100
1 time/month
23
96
0
0
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13. Children’s activities
Activities
Study area
Significance
Rice area
Aquaculture area
(n=24)
(n=29)
(χ2 test)
n
%
n
%
P
Washing hand before
consuming meals
13
54.2
21
72.4
0.36
Playing on rice farm
12
52.2
5
17.9
0.01
Observable dirt on body
19
82.6
16
57.1
0.05
 No significant differences in the time spent in play (indoors or
outdoors) and object-to-mouth behavior.
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14. Concentrations of organophosphate metabolites in urine
samples
Rice children had significantly higher DAP concentrations compared with
aquaculture children (Mann-Whitney U test; p<0.05).
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15. Concentrations of organophosphate metabolites in urine samples
 Diethylthiophosphate (DETP) and diethylphosphate
(DEP) were commonly found in urine samples.
 DEP and DETP had a positively correlation with DAPs
(DEP; rho=0.92, p<0.001, DETP; rho=0.69, p<0.001).
 Suggesting that the primary OP to which participants
were exposed was chlorpyrifos.
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16. Relationship between children’s
environment and activities with pesticide
exposure

From linear regression analysis, DAP concentrations had
significant associations with being a member of rice farming
family (β=0.32, p=0.02) and frequency of OP use on farms
(β=0.39, p=0.006).
Children
of rice farmers lived in closer proximity to farms, spent
more time played while parents worked on the farm and tended
to have more dirt on their bodies.
Take-home
contaminants from farmers to their family member
was a possible pathway of OP exposure.
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17. Conclusions
 Children living near rice field had higher OP exposure
than who living near aquacultural areas.
 The levels of OP metabolites in participants living near
rice areas also greater than other areas in Thailand.
 The risk of pesticide exposure is undoubtedly a concern
that require public health attention.
 The neurobehavioral deficits among children with longterm OP exposure will be our further study.

18. Acknowledgements

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
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The NIH research grant (NIEHS R21ES18722)
Thai Fogarty International Training and Research in
Environmental and Occupational Health (ITREOH grant
number D43TW007849-01NIHFIC)
The 90th Anniversary of Chulalongkorn University grant
Conference grant for Ph.D. student, Graduate School,
Chulalongkorn University

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