Human health hazard: the registered pesticides from globally harmonized system of classification and labelling of chemicals (GHS) in Malaysia

In Malaysia, chemical pesticides are widely used not only for agricultural development, but also to public health, household to control diseases, pests or weeds. In order to ensure that the information of the pesticides’ hazard properties conveyed to all pesticide users, the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) has initiated to promote standard criteria for classifying chemicals according to human health, physical and environmental hazards. Even though statuses of GHS implementation on pesticides are remained unstandardized across different countries, Malaysia has taken proactive measures to implement the GHS at the workplace through the promulgation of the Occupational Safety and Health (Classification, Labelling and Safety Data Sheet of Hazardous Chemicals) Regulations 2013 (CLASS Regulations). This paper attempted to summarize the health hazards of pesticide chemicals registered in Malaysia by summarizing the nature of the registered pesticides’ hazards classification based on GHS in order to understand the current situation of GHS adoption in pesticides sector in the country. Overall, registered pesticides in Malaysia are known to cause either acute or chronic health effects. Out of 3,610 pesticides registered under the Pesticide Board, a total of 2,241 pesticides are listed as highly hazardous pesticides (HHP). Even though GHS includes appropriate labelling tools to convey information about each of the hazard classes and categories, several limitations have found when classifying appropriate hazard class and categories to individual pesticides

Ultra high performance liquid chromatography technique to determine imidacloprid residue in rice using QuEChERS method

Imidacloprid residue analysis in paddy samples was conducted using the simplified and validated QuEChERS preparation method. Samples were extracted with acetonitrile (ACN) and salts anhydrous magnesium sulphate (MgSO4) and sodium chloride (NaCI) while cleaning was by treating with primary secondary amine (PSA). Imidacloprid residue was quantified with Ultra High Performance Liquid Chromatography (UHPLC) using short and narrow C18 column to reduce analysis duration and solvent consumption. The pumps were programmed to mix acetonitrile and water at a ratio of 2:8 to form the mobile phase, with a flow rate of 0.1 mL/min and10 μl injection volumes. Imidacloprid was detected at 270 nm using UV detector. The method was validated in term of linearity, range, limit of detection (LOD), limit of quantification (LOQ), precision (repeatability and intermediate precision), and accuracy (recovery). The LOD was 0.001 mg/L whereas LOQ was 0.003 mg/L. The validated method provides good analytical results wherein the linearity r2 was 0.9996, recoveries 80−120% and RSDs <20%. This method can be implemented in routine laboratories as it yields a higher sample throughput and reduced solvent consumption compared to the traditional Luke method approach

Blood cholinesterase concentration and neurobehavioral performance of primary schoolchildren at Tanjung Karang, Malaysia

Background: Organophosphate pesticide is widely used to protect plants from pest are numerously used in agricultural activity. However, organophosphate also found to cause harm on human such as impaired neurobehavioral performance after prolonged chronic exposure. Objective: This study was aim was to determine the cholinesterase level and the relationship with neurobehavioral performance. Results: Result showed a significant difference in blood cholinesterase concentrations between the exposed and unexposed group (χ2=39.822, p=<0.001). The total score of NCTB test showed that the exposed group (351.08) score was significantly lower than the unexposed group (365.93). Reaction Time Test showed significant difference between the exposed and unexposed group. There was also significant relationship between blood cholinesterase concentration and Pursuit Aiming Test (p<0.001). Housing area (p=0.017), total household income (p=0.011), father's occupation (p=0.012) and mother's occupation (p=0.001) were confounders which have influenced the blood cholinesterase concentrations. Conclusion: Blood cholinesterase have significantly influenced the Pursuit Aiming Test scores which reflected on the impairment of motor steadiness

Health Risk Assessment of Rice Consumption: Analysis of Imidacloprid Residue in Paddy and Rice from Tanjung Karang, Selangor

50 samples of paddy, brown rice and white rice were collected from paddy fields in Tanjung Karang, Selangor and were analysed for imidacloprid residues. This study objective was to evaluate the non-carcinogenic health risks on Tanjung Karan

The chromosomal DNA damage in buccal mucosa cells among schools children in the vicinity of mobile base stations in Selangor

Introduction: The increased use of mobile phones has increased the mobile base stations (MBS) deployment. While understanding of radiation protection is growing among the public, questions regarding early-life exposure to radiofrequency radiation (RFR) from MBS in children are of importance as to whether it will raise the chances of developing chronic diseases during adulthood. Taking into account the sitting location of MBS, the purpose of this study is to evaluate the chromosomal DNA damage in buccal mucosal cells between school children exposed to RFR emitted from base station antennas. Method: This is a comparative cross-sectional study in which two group of school children were sampled i.e. exposed groups are children whose school located near MBS (≤200 meters); unexposed groups are children whose school located distant far from the MBS (>200 meters). Digital RF Analyzer was used to measure RFR at the school surrounding. Buccal mucosa cells from the oral cavity were sampled to examine the level of micronuclei (MN) frequencies. Results: This study found that the densities of the RFR energy differed in range. Although all measurements showed the RFR reading below the acceptable exposure level, there were still significant variations at each location assessed. Statistically, the MN frequency is significantly different when compared to the exposed and non-exposed group. Conclusion: To understand the mechanism of health effects from exposure to low-level RFR emited from MBS, further study should consider environmental factors influencing MBS sitting on RFR emission, as well as examining the health effects into molecular levels

Imidacloprid residue in paddy, unpolished and polished rice, and health risk assessment of rice consumption in Tanjung Karang, Malaysia

Background: Rice (Oryza sativa L.) by large is staple food consumed and produced by most of the world population including Malaysia. In order to combat from brown planthoppers attack, farmers have used imidacloprid in the paddy fields. However, the used of imidacloprid might give some effect to the population that consume rice. Objective: The objective of this study was to evaluate the non-carcinogenic health risks on Tanjung Karang’s population (n=552) through rice consumption. Methodology: Fifty samples of paddy, unpolished rice and polished rice were collected from paddy fields and milling factory in Tanjung Karang, Selangor and were analysed for imidacloprid residues. The population was divided into 3 age groups which are adult, teenagers and children. Imidacloprid residue analysis in paddy and rice samples was conducted using the simplified and validated QuEChERS (quick, easy, cheap, effective, rugged, and safe) preparation method. Samples were extracted with acetonitrile (ACN) and salts anhydrous magnesium sulphate (MgSO4) and sodium chloride (NaCI) while cleaning was by treating with primary secondary amine (PSA). Imidacloprid residue was quantified with Ultra High Performance Liquid Chromatography (UHPLC) using C18 column and UV detector. The method was validated in term of linearity, range, limit of detection (LOD), limit of quantification (LOQ), precision (repeatability and intermediate precision), and accuracy (recovery). LOD and LOQ and of the method was 0.001 mg/L and 0.003 mg/L, respectively. Result: The validated method provides good analytical results wherein the linearity r2 was 0.9996, recoveries 80−120 % and RSDs <20%. Through of this method, imidacloprid residue was detected in 20%, 14% and 10% of paddy samples, unpolished rice and polished rice, respectively with 4% of the total samples exceeded the MRL. The mean imidacloprid concentration was 0.14 mg/kg in the paddy sample, 0.04 mg/kg in unpolished rice sample and 0.03 mg/kg in polished rice sample. The EDI for adult, adolescent and children were 0.08 mg/kg, 0.03 mg/kg and 0.0002 mg/kg, respectively. HQ value of adult was 1.32 showed that this group was exposed to non-carcinogenic health risk through rice consumption. Conclusion: The result of analysis showed that imidacloprid residues were present in paddy and rice samples originate from Tanjung Karang paddy cultivation area. Imidacloprid was detected in mostly in paddy samples compared to brown rice and white rice, respectively with 4% of the total samples exceeded the Malaysian Residue Level (MRL). This indicates that routine monitoring of this contaminants in food items is required to prevent, control and reduce the contamination and to minimize health risks. This research has provided important information on imidacloprid residues contamination on local paddy and rice for the first time

Blood cholinesterase level and learning ability of primary school children in an agricultural village, Tanjung Karang, Malaysia

Objective: The widespread use of organophosphate (OP) insecticides in paddy fields has led to human exposure. The aim of this study was to determine the relationship between blood cholinesterase concentrations with the children’s learning ability in the agricultural village of Tanjung Karang, Selangor. Methods: Seventy-seven primary school children who live less than approximately 1km from paddy fields were selected as the exposed group, while another 62 primary schoolchildren who live more than 1 km away from the agriculture site served as the unexposed group. The questionnaires were completed by the parents. The children’s capillary blood was collected using the finger prick technique to determine the blood cholinesterase concentrations using a cholinesterase test kit (Lovibond, AF267, Tintometer Ltd., UK). The McCarthy Scales of Children’s Abilities (MSCA) were used to determine the learning ability of these children. Results: There were significant differences (p<0.05) in blood cholinesterase and all scales in the MSCA between the exposed and the unexposed group. There were significant associations between the blood cholinesterase concentrations and learning ability by all scales in the MSCA (p<0.05). The variable that significantly influenced the blood cholinesterase was gender (p=0.008). Blood cholinesterase was the most significant influencing factor on the learning ability, especially on the motor scale (p=0.002). Conclusion: Blood cholinesterase concentrations were significantly higher and had a significant relationship with the learning ability of the exposed group, especially the motor performance

Association of blood cholinesterase with sexual differences in metabolic health risks among villagers from pesticide-treated farming villages

The physiological differences between men and women have resulted in discrepancies of pesticides' toxicokinetic and toxicodynamic mechanism. It is speculated that women are more prone to exposure to pesticides than men, which increases the risks to their metabolic health. This study aims to establish a link between long-term, low-level exposure to pesticides and its potential adverse metabolic health risks in farming villages by using the parameters of body composition and acetylcholinesterase activity as indicators. The result indicates that the blood cholinesterase levels in males are proportionally lower than in females. The distinction of farmer and non-farmer as an occupation often shows a different degree of metabolic health symptoms unique to the sex. In addition, the sexual differences in the correlation of the level of blood cholinesterase with the body mass index, visceral muscle, body fat and visceral fat among the farming communities in the same farming village are of considerable interest. These findings provide a mechanistic explanation for women's vulnerability to pesticide exposure and indicate potential opportunities for early prevention and surveillance for these working women in the farming community