Determination of blood cholinesterase, neurobehavioral performance and genetic damage due to organophosphate exposure among male cocoa farmers in Pahang and Perak, Malaysia
Cocoa plantation farmers in Malaysia are continually being exposed to Organophosphate (OP) insecticide. Chlorpyrifos (group II) is an example of OP used in cocoa farms, and this chemical categorized as a moderately hazardous substance that may cause severe health effects to the plantation workers...
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Zainal Abidin, Emilia |
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Organophosphates Insecticides - radiation effects |
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Organophosphates Insecticides - radiation effects Mohammad, Norsyazwani Determination of blood cholinesterase, neurobehavioral performance and genetic damage due to organophosphate exposure among male cocoa farmers in Pahang and Perak, Malaysia |
| description |
Cocoa plantation farmers in Malaysia are continually being exposed to
Organophosphate (OP) insecticide. Chlorpyrifos (group II) is an example of OP
used in cocoa farms, and this chemical categorized as a moderately hazardous
substance that may cause severe health effects to the plantation workers such
as effects to the neurological system, reproductive system, hormonal changes
and development of cancer. There are approximately 12,839 workers which is
inclusive of cocoa farmers working with cocoa centre and independent
smallholder cocoa farmers in Malaysia who are working in the cocoa plantations
sector with the breakdown of 4,881 workers in Sabah, 5,613 workers in Sarawak
and 2,345 (18.3%) workers in the Peninsular Malaysia. Cocoa farmers are
considered at-risk for exposures to OP insecticides from activities such as
mixing, spraying, cleaning, loading and disposal process at the workplace. It is
imperative for studies to be implemented to find out how the exposure of cocoa
farmers to OP pesticides may impact their health and safety, as there are
currently no data available and focusing on that. Hence, the study was performed
to assess the acute and chronic health effects among male cocoa farmers in
Perak and Pahang, Malaysia over the period of exposure to OP in cocoa
plantation. The blood cholinesterase level and neurobehavioral performance
were used as indicators to determine the acute health effects, while genetic
damage assessment was further conducted to determine the chronic health
effects of the substance. This is a cross-sectional study among the male cocoa
farmers who are working in the fields at the Cocoa Research and Development
Centre in Jengka, Pahang and Bagan Datuk, Perak, Malaysia. This study is
divided into three interlinked sub-studies: namely i) sociodemographic and
occupational background distribution of respondents, ii) evaluation of OP
exposure level, and iii) analysis of health effects linked to the OP exposure. A
simple randomized method was applied in recruiting male cocoa farmer respondents (n=102). In Sub-study I, a structured questionnaire was
administered to obtain individual, residential and occupational information. In
Sub-study II, blood samples were collected via finger prick technique to evaluate
acute OP exposure via determination of cholinesterase level. Calculations to
estimate the intensity level of insecticide exposure were performed by using
information obtained in sub-study 1 and used in an established algorithm. In Substudy
III, Neurobehavioral Core Test Battery (NCTB) was used to measure the
neurobehavioral performance. NCTB is one of the test batteries that are
designed to assess the neurobehavioral performances on the human nervous
system to assess effects due to neurotoxic chemicals exposures. There are
seven subtests of NCTB which were included in this study. Buccal epithelial cell
samples (n=97) were swabbed to identify genetic damage from chronic exposure
to OP through comet and micronuclei (MN) assays. The average age of cocoa
farmers was at 36.54±9.93 years old. The most common health symptoms facing
by cocoa farmers were burning sensation in the face (57.8%), dizziness (51%),
skin rashes and fatigue (38.2%), and headache and coughing (32.4%). In Substudy
II, the median (interquartile range, IQR) estimation for intensity level of OP
exposure among the cocoa farmers was 15.60 (16.0), with 52% of them were
categorized as having a low-intensity level. The mean (SD) of blood
cholinesterase levels among cocoa farmers group was 87.01 (13.15) in
percentage which corresponding with the normal range. About 7.8% of cocoa
farmers had abnormal levels. OP exposure had given poor performance on
motor functionality and manual dexterity of cocoa farmers. In logistic regression,
factors such as length of tenure showed statistically significant contribution to
the performance on visual-motor speed (adjusted odds ratio (AOR) 0.18, 95%
confidence interval (CI), 0.05-0.66) and motor steadiness (AOR 0.14; 95%CI,
0.04-0.54). In comparison, the age variable was contributing significantly to the
reporting of manual dexterity performance (AOR 0.11; 95%CI, 0.01-1.01). In
Sub-study III, the comet tail length values ranged between 12.06 and 35.27 μm
(mean: 22.63 μm), whereas the percentage of DNA in the tail ranged between
16.79% and 53.69% (mean: 33.82%). Cocoa farmers reported an average MN
frequency (per 1000 cells) with 8.51±3.99. Meanwhile, the blood cholinesterase
level (odds ratio (OR) -0.12, 95% confidence interval (CI), -0.20- (-0.66) , p<0.01
and OR -0.13; 95%CI, -0.23- (-0.04), p<0.01), smoking duration (OR -0.23;
95%CI, -0.43- (-0.02), p<0.05), and appropriate personal protective equipment
(PPE) (OR -10.14; 95%CI, -17.55- (-2.72), p<0.01), were among the significant
predictive factors that contributed to 13% of the comet assay formation (e.g.
comet tail length and the percentage of DNA in the tail). On the other hand,
approximately 20.8% of MN frequency variation were explained by age (OR 0.10;
95%CI, -0.01-0.20), p<0.05), BMI (OR 0.26; 95%CI, 0.09-0.43), p<0.01),
smoking habit (OR 5.19; 95%CI, 2.07-8.32), p<0.01) and smoking duration (OR
-0.23; 95%CI, -0.37-(-0.08), p<0.01) among the cocoa farmers. In summary, the
cocoa management has established good labour practices and guidelines for
cocoa farmers to follow when handling pesticides. This is evidenced by the fact
that majority of cocoa farmers had normal blood cholinesterase levels despite
being constantly exposed to OP as part of their work. Most of them were slightly
exposed to pesticides, but some of them showed poor motor functionality and
manual dexterity. There are other factors might contribute to poor motor
functionality and manual dexterity such as the environment, genetics and their
lifestyle. This study suggests that the neurobehavioral assessments and genetic
damage measurements conducted have provided insight into the need for early detection and screening of minor exposures to OP in cocoa farmers. The
management need to provide necessary chemical-resistant PPE to cocoa
farmers such as nitrile glove and respirator with filter. Besides there are also
necessary to implement periodically monitoring health risk among cocoa farmers in the future. |
| format |
Thesis |
| qualification_level |
Doctorate |
| author |
Mohammad, Norsyazwani |
| author_facet |
Mohammad, Norsyazwani |
| author_sort |
Mohammad, Norsyazwani |
| title |
Determination of blood cholinesterase, neurobehavioral performance and genetic damage due to organophosphate exposure among male cocoa farmers in Pahang and Perak, Malaysia |
| title_short |
Determination of blood cholinesterase, neurobehavioral performance and genetic damage due to organophosphate exposure among male cocoa farmers in Pahang and Perak, Malaysia |
| title_full |
Determination of blood cholinesterase, neurobehavioral performance and genetic damage due to organophosphate exposure among male cocoa farmers in Pahang and Perak, Malaysia |
| title_fullStr |
Determination of blood cholinesterase, neurobehavioral performance and genetic damage due to organophosphate exposure among male cocoa farmers in Pahang and Perak, Malaysia |
| title_full_unstemmed |
Determination of blood cholinesterase, neurobehavioral performance and genetic damage due to organophosphate exposure among male cocoa farmers in Pahang and Perak, Malaysia |
| title_sort |
determination of blood cholinesterase, neurobehavioral performance and genetic damage due to organophosphate exposure among male cocoa farmers in pahang and perak, malaysia |
| granting_institution |
Universiti Putra Malaysia |
| publishDate |
2022 |
| url |
http://psasir.upm.edu.my/id/eprint/103797/1/NORSYAZWANI%20BINTI%20MOHAM%20-%20IR.pdf |
| _version_ |
1776100363525423104 |
| spelling |
my-upm-ir.1037972023-04-17T07:06:32Z Determination of blood cholinesterase, neurobehavioral performance and genetic damage due to organophosphate exposure among male cocoa farmers in Pahang and Perak, Malaysia 2022-01 Mohammad, Norsyazwani Cocoa plantation farmers in Malaysia are continually being exposed to Organophosphate (OP) insecticide. Chlorpyrifos (group II) is an example of OP used in cocoa farms, and this chemical categorized as a moderately hazardous substance that may cause severe health effects to the plantation workers such as effects to the neurological system, reproductive system, hormonal changes and development of cancer. There are approximately 12,839 workers which is inclusive of cocoa farmers working with cocoa centre and independent smallholder cocoa farmers in Malaysia who are working in the cocoa plantations sector with the breakdown of 4,881 workers in Sabah, 5,613 workers in Sarawak and 2,345 (18.3%) workers in the Peninsular Malaysia. Cocoa farmers are considered at-risk for exposures to OP insecticides from activities such as mixing, spraying, cleaning, loading and disposal process at the workplace. It is imperative for studies to be implemented to find out how the exposure of cocoa farmers to OP pesticides may impact their health and safety, as there are currently no data available and focusing on that. Hence, the study was performed to assess the acute and chronic health effects among male cocoa farmers in Perak and Pahang, Malaysia over the period of exposure to OP in cocoa plantation. The blood cholinesterase level and neurobehavioral performance were used as indicators to determine the acute health effects, while genetic damage assessment was further conducted to determine the chronic health effects of the substance. This is a cross-sectional study among the male cocoa farmers who are working in the fields at the Cocoa Research and Development Centre in Jengka, Pahang and Bagan Datuk, Perak, Malaysia. This study is divided into three interlinked sub-studies: namely i) sociodemographic and occupational background distribution of respondents, ii) evaluation of OP exposure level, and iii) analysis of health effects linked to the OP exposure. A simple randomized method was applied in recruiting male cocoa farmer respondents (n=102). In Sub-study I, a structured questionnaire was administered to obtain individual, residential and occupational information. In Sub-study II, blood samples were collected via finger prick technique to evaluate acute OP exposure via determination of cholinesterase level. Calculations to estimate the intensity level of insecticide exposure were performed by using information obtained in sub-study 1 and used in an established algorithm. In Substudy III, Neurobehavioral Core Test Battery (NCTB) was used to measure the neurobehavioral performance. NCTB is one of the test batteries that are designed to assess the neurobehavioral performances on the human nervous system to assess effects due to neurotoxic chemicals exposures. There are seven subtests of NCTB which were included in this study. Buccal epithelial cell samples (n=97) were swabbed to identify genetic damage from chronic exposure to OP through comet and micronuclei (MN) assays. The average age of cocoa farmers was at 36.54±9.93 years old. The most common health symptoms facing by cocoa farmers were burning sensation in the face (57.8%), dizziness (51%), skin rashes and fatigue (38.2%), and headache and coughing (32.4%). In Substudy II, the median (interquartile range, IQR) estimation for intensity level of OP exposure among the cocoa farmers was 15.60 (16.0), with 52% of them were categorized as having a low-intensity level. The mean (SD) of blood cholinesterase levels among cocoa farmers group was 87.01 (13.15) in percentage which corresponding with the normal range. About 7.8% of cocoa farmers had abnormal levels. OP exposure had given poor performance on motor functionality and manual dexterity of cocoa farmers. In logistic regression, factors such as length of tenure showed statistically significant contribution to the performance on visual-motor speed (adjusted odds ratio (AOR) 0.18, 95% confidence interval (CI), 0.05-0.66) and motor steadiness (AOR 0.14; 95%CI, 0.04-0.54). In comparison, the age variable was contributing significantly to the reporting of manual dexterity performance (AOR 0.11; 95%CI, 0.01-1.01). In Sub-study III, the comet tail length values ranged between 12.06 and 35.27 μm (mean: 22.63 μm), whereas the percentage of DNA in the tail ranged between 16.79% and 53.69% (mean: 33.82%). Cocoa farmers reported an average MN frequency (per 1000 cells) with 8.51±3.99. Meanwhile, the blood cholinesterase level (odds ratio (OR) -0.12, 95% confidence interval (CI), -0.20- (-0.66) , p<0.01 and OR -0.13; 95%CI, -0.23- (-0.04), p<0.01), smoking duration (OR -0.23; 95%CI, -0.43- (-0.02), p<0.05), and appropriate personal protective equipment (PPE) (OR -10.14; 95%CI, -17.55- (-2.72), p<0.01), were among the significant predictive factors that contributed to 13% of the comet assay formation (e.g. comet tail length and the percentage of DNA in the tail). On the other hand, approximately 20.8% of MN frequency variation were explained by age (OR 0.10; 95%CI, -0.01-0.20), p<0.05), BMI (OR 0.26; 95%CI, 0.09-0.43), p<0.01), smoking habit (OR 5.19; 95%CI, 2.07-8.32), p<0.01) and smoking duration (OR -0.23; 95%CI, -0.37-(-0.08), p<0.01) among the cocoa farmers. In summary, the cocoa management has established good labour practices and guidelines for cocoa farmers to follow when handling pesticides. This is evidenced by the fact that majority of cocoa farmers had normal blood cholinesterase levels despite being constantly exposed to OP as part of their work. Most of them were slightly exposed to pesticides, but some of them showed poor motor functionality and manual dexterity. There are other factors might contribute to poor motor functionality and manual dexterity such as the environment, genetics and their lifestyle. This study suggests that the neurobehavioral assessments and genetic damage measurements conducted have provided insight into the need for early detection and screening of minor exposures to OP in cocoa farmers. The management need to provide necessary chemical-resistant PPE to cocoa farmers such as nitrile glove and respirator with filter. Besides there are also necessary to implement periodically monitoring health risk among cocoa farmers in the future. Organophosphates Insecticides - radiation effects 2022-01 Thesis http://psasir.upm.edu.my/id/eprint/103797/ http://psasir.upm.edu.my/id/eprint/103797/1/NORSYAZWANI%20BINTI%20MOHAM%20-%20IR.pdf text en public doctoral Universiti Putra Malaysia Organophosphates Insecticides - radiation effects Zainal Abidin, Emilia |