2 Research Articles on Pesticide Related Issues in

CambodiaYearend 2010/2011

Winfried Scheewe/COrAA - PRN Meeting 28/02/2011

1. Pesticide Use and Self-Reported Symptoms of Acute Pesticide Poisoning among Aquatic Farmers in Phnom Penh, Cambodia by Hanne K. Jensen et al.

2. Prevalence and Persistence of Organophosphate and Carbamate Pesticides in Cambodian Market Vegetables by D.S.G. Neufeld et al.

Pesticide Use among Aquatic Farmers

Phnom Penh Post, 11 January 2011

Some Findings

Frequent use of the most toxic insecticides based on the WHO classification • Ia + Ib which are, respectively,

extremely and highly hazardous and

• Class II which are moderately hazardous

• Both classes are banned or have restricted use in Cambodia

Insecticides used by 93 households in Boeung Cheung Ek Lake

Personal protective measures adapted by 89 farmers inrelation to spraying pesticides in Boeung Cheung EK Lake

Some Findings (2)

Pesticides Residues in Vegetables Research Article:

Prevalence and Persistence of Organophosphate and Carbamate Pesticides in Cambodian Market Vegetables

D.S.G. Neufeld*, H. Savoeun1, C. Phoeurk1, A. Glick2 and C. Hernandez3Department of Biology, Eastern Mennonite University, Harrisonburg, Virginia, USA1Department of Chemistry, Royal University of Phnom Penh, Cambodia2Department of Chemistry, Eastern Mennonite University, Harrisonburg, Virginia, USA3Department of Chemistry, Buffalo State College, Buffalo, New York, USA

Asian Journal of Water, Environment and Pollution, Vol. 7, No. 4, pp. 89-98.

Probably the first research article on Pesticide residues in Cambodian Market Vegetables

Carbamate insecticides

• kill insects by reversibly inactivating the enzyme acetylcholinesterase.

• They are relatively unstable compounds that break down in the environment within weeks or months.

Organophosphates

Examples• Insecticides including

malathion, parathion, diazinon, fenthion, dichlorvos, chlorpyrifos, ethion

• Herbicides including tribufos [DEF]

One of the products of the reaction of Fc2P2S4 with dimethyl cyanamide

Concerns of the Study

• Widespread use of pesticides on vegetable crops

• Likely that vegetables sold in Cambodian markets could contain pesticide residues …

• … but very little information available on actual levels of pesticides

• Pesticide measurements generally require special skills and equipment

• Cambodia has lacked the capacity to conduct regular monitoring

critical information on the prevalence of pesticide residues is lacking

Concerns of the Study

Second round:screening test indi-cated presence of pesticide residue– in 88% of curly-leafed

kale, – 95% of white-

stemmed kale– and 93% of Chinese

broccoli samples

Results of the study

Long bean shows the fewest responses for pesticides residue, with no samples showing unsafe levels

Two rounds of screening indicate that 1. Consumers are

regularly exposed to pesticide residues in local vegetables

2. Significant variation in levels of pesticide residues

Results of the study

• Farm Trials for OP/C Sprayed on Water Spinach confirm a clear trend in methyl parathion disappearance

Results of the study

• Pesticide residues are widespread in market vegetables

• Consumers are likely exposed to these pesticide residues, although the

• Screening tests used in this study do not indicate the level of health risk associated with the residues in market vegetables

Conclusion (1)

• Need to consider both toxicity and persistence in assessing the impacts associated with residues on vegetables

Conclusion (2)

• Contexts: lower resources and capacity

• Screening of vegetable samples with simpler test methods (such as the cholinesterase inhibition assay) coupled with targeted analysis of samples of concern can …

• … provide information about prevalence and magnitude of residues, at a lower investment of resources and time

Conclusion (3)

Appropriate pesticide monitoring strategy

Effects• Exposure to

organophosphates chronic fatigue symptoms

• A 2010 study: Organophosphate exposure is associated with an increased risk of Alzheimer's disease

• Organophosphate insecticide chlorpyrifos, (used on fruits and vegetables) delays in learning rates, reduced physical coordination, and behavioral problems in children

Recent Findings on Effects

Effects

Attention deficit hyperactivity disorder (ADHD)

A 2010 study:organophosphate exposure is associated with an increased risk of ADHD in children.

organophosphate residues in the urine of children aged 8 to 15 years old:those with the highest levels of dialkyl phosphates – a breakdown product of organo-phosphate pesticides - also had the highest incidence of ADHD

Recent Findings on Effects

Recent Findings on Effects

Scientists from University of London’s Centre for Toxicology found:30 out of 37 pesticides blocked or mimicked male hormones, including 16 that had no known hormonal activity until now.