A new method for setting guidelines to protect human health from agricultural exposure by using chlorpyrifos as an example

Introduction and objectives Guidelines set by various agencies for the control and management of chlorpyrifos cover a wide range of values reflecting difficulties in the procedures for their development. To overcome these difficulties a new method to set guidelines would be developed. Published data derived from epidemiological investigations on human populations would be used to develop a dose-response relationship for chlorpyrifos allowing the calculation of threshold values which can be used as guidelines. Material and Methods Data from the scientific literature on human populations were collected to evaluate the adverse response doses for a range of health effects. The Cumulative Frequency Distribution (CFD) for the minimum levels of adverse effects measured in terms of the Lifetime Average Daily Dose (LADD[sub]D[/sub]) and the Absorbed Daily Dose for neurological (ADD[sub]DN[/sub]) and non-neurological effects were used. Results Linear regression equations were fitted to the CFD plots giving R 2 values of 0.93 and 0.86 indicating a normal distribution of the data. Using these CFD plots, the chronic and acute threshold values were calculated at the 5% cumulative frequency level for chlorpyrifos exposure giving values at 0.5 µg/kg/d and 3 µg/kg/d respectively. Conclusions Guidelines set using this technique at the values at 0.5 µg/kg/d and 3 µg/kg/d for chronic and acute exposure respectively provide an alternative to the currently used biological endpoint and safety factor method

Health risk due to exposure to chlorpyrifos for farmers in Thai Binh: Probabilistic risk assessment

Farmers in Vietnam are at high risk of exposure to pesticides, especially with chlorpyrifos, the most common insecticide registered for use in 2009 in Vietnam. The purpose of this study was to assess the health risks of chlorpyrifos exposure in farmers who were pesticide applicators. The research method included three steps: (i) 24-hour urine samples taken from farmers to analyse trichlorpyridinol (TCP), the main metabolite of chlorpyrifos, and then TCP was converted to Absorbed Daily Dose (ADD); (ii) dose-response (RADD) corresponding to acute effects on the nervous system was obtained and recalculated from epidemiologic studies on human population; (iii) the health risk of chlorpyrifos with farmers was evaluated using probabilistic health risk assessment approach with 10,000 trials simulated by Monte Carlo technique. The results showed that the baseline exposure level (ADDB) ranged from 0.03 - 1.98 µg/kg/d, and post-application exposure level (ADDA) ranged from 0.35 - 94 µg/kg/d. The total exposure level (ADDT), ranged from 0.4 - 94.2 µg/kg/d. Dose-response corresponding to neurological adverse effects (RADD) ranged from 5-181 µg/kg/d. The Hazard Quotient calculated from ADD and RADD revealed that the baseline exposure level did not contribute to a significant adverse effect, however the post-application and total exposure levels caused a high risk of adverse effects to farmers who were pesticide applicators at 33%. A needs assessment and intervention studies need to be conducted to explore methods to reduce the risks due to chlorpyrifos exposure among farmers

Pesticide regulations and farm worker safety: the need to improve pesticide regulations in Viet Nam

Agricultural pesticide use in Viet Nam has more than tripled since 1990. However, pesticide legislation and regulations have not been developed in response to this large increase in usage, as a result of which pesticides pose a serious threat to human health and the environment. This paper identifies the need to improve pesticide regulations in Viet Nam through a comparative analysis of pesticide regulations in Viet Nam and the United States of America, where the rate of acute poisoning among agricultural workers is much lower than in Viet Nam and where information pertaining to pesticide regulations is made accessible to the public. The analysis identified several measures that would help to improve Viet Nam’s pesticide regulations. These include enhancing pesticide legislation, clarifying the specific roles and active involvement of both the environmental and health sectors; performing a comprehensive risk–benefit evaluation of pesticide registration and management practices; improving regulations on pesticide suspension and cancellation, transport, storage and disposal; developing import and export policies and enhancing pesticide-related occupational safety programmes

SOLUTIONS TO IMPROVING THE ADOLESCENT’S MENTAL HEALTH BY THE IMPACT OF COVID-19 IN GIA LAI, VIETNAM FOLLOWING “STRATIFIED COMMUNICATIONS MODEL”

COVID-19 endangers people's lives and causes many mental health problems for society, especially for young people. Adolescents’ awareness of this problem is essential to control the pandemic and improve their mental health. This study aims to apply a stratified communication model to affect knowledge, attitude, and practice (KAP) about COVID-19 and evaluate their effects on adolescents' mental health. A cross-sectional study was conducted before and after the intervention based on questionnaires and online and in-person activities launched in Gia Lai from August to December 2021. Students attending Hung Vuong High School for the Gifted (Ts), a community teen group (Tc), and their parents (Ps and Pc) were invited to participate in this study. Most participants (82.5% of Ts and 52.4% of Tc) comply with the pandemic prevention regulations. COVID-19 affected adolescents’ mental health that caused worry, fear, and loss of attention in 76.1% of Ts and 80% of Tc. The results also illustrated that the KAP of Tc was lower than that of Ts, and their academic level influenced the KAP. After the stratified communication intervention, the KAP of the participants, as well as their mental health improved. This model offers a solution to the minimal impact of COVID-19 on young people and the control of this pandemic

Environmental monitoring and potential health risk assessment from Pymetrozine exposure among communities in typical rice-growing areas of China

Pymetrozine is one of the most commonly used insecticides in China. This study was conducted to analyse Pymetrozine's potential exposures through various environmental routes beyond the treatment areas. The aim was to estimate the potential health risk for communities due to non-dietary exposures to Pymetrozine in soil and paddy water. Data on registration of pesticides in China, government reports, questionnaires, interviews and literature reviews as well as toxicological health investigations were evaluated to determine the hazard and dose-response characteristics of Pymetrozine. These were based on the US EPA exposure and human health risk assessment methods and exposure data from soil and paddy water samples collected between 10 and 20 m around the resident's location. The exposure doses from dermal contact through soil and paddy water were estimated. The potential cancer risk from the following exposure routes was evaluated: ingestion through soil; dermal contact exposure through soil; dermal contact exposure through paddy water. The potential total cancer risk for residents was estimated to be less than 1 × 10-6. These were relatively low and within the acceptable risk levels. The potential hazard quotient (HQ) from acute and lifetime exposure by dermal contact through paddy water and soil and acute and lifetime exposure by soil ingestion for residents was less than 1, indicating an acceptable risk level. This study suggested that there were negligible cancer risk and non-cancer risks based on ingestion and dermal contact routes of exposure to residents

Exposure Routes and Health Risks Associated with Pesticide Application

Pesticides play an important role in agricultural development. However, pesticide application can result in both acute and chronic human toxicities, and the adverse effects of pesticides on the environment and human health remain a serious problem. There is therefore a need to discuss the application methods for pesticides, the routes of pesticide exposure, and the health risks posed by pesticide application. The health problems related to pesticide application and exposure in developing countries are of particular concern. The purpose of this paper is to provide scientific information for policymakers in order to allow the development of proper pesticide application technics and methods to minimize pesticide exposure and the adverse health effects on both applicators and communities. Studies indicate that there are four main pesticide application methods, including hydraulic spraying, backpack spraying, basal trunk spraying, and aerial spraying. Pesticide application methods are mainly selected by considering the habits of target pests, the characteristics of target sites, and the properties of pesticides. Humans are directly exposed to pesticides in occupational, agricultural, and household activities and are indirectly exposed to pesticides via environmental media, including air, water, soil, and food. Human exposure to pesticides occurs mainly through dermal, oral, and respiratory routes. People who are directly and/or indirectly exposed to pesticides may contract acute toxicity effects and chronic diseases. Although no segment of the general population is completely protected against exposure to pesticides and their potentially serious health effects, a disproportionate burden is shouldered by people in developing countries. Both deterministic and probabilistic human health risk assessments have their advantages and disadvantages and both types of methods should be comprehensively implemented in research on exposure and human health risk assessment. Equipment for appropriate pesticide application is important for application efficiency to minimize the loss of spray solution as well as reduce pesticide residuals in the environment and adverse human health effects due to over-spraying and residues. Policymakers should implement various useful measures, such as integrated pest management (IPM) laws that prohibit the use of pesticides with high risks and the development of a national implementation plan (NIP) to reduce the adverse effects of pesticides on the environment and on human health

SOLUTIONS TO IMPROVE AWARENESS AND IMPROVE KNOWLEDGE, ATTITUDE, PRACTICE (KAP) ABOUT COVID-19 FOR ETHNIC MINORITY PEOPLES IN GIA LAI PROVINCE, VIETNAM

COVID-19 is a global health threat and an international public health emergency. Right awareness, good knowledge, positive attitude, and good practice are one of the central issues to ensure the successful prevention and control of the COVID-19 pandemic. However, in some remote rural areas with difficult living conditions, social media about COVID-19 has not reached them. So, this study aims to present a possible solution to improve their awareness about COVID-19 among ethnic minorities in Gia Lai province, Vietnam. This study was conducted with 674 people in the community from September 1 to December 20, 2021. An intervention design using the stratified communication model and structured questionnaire was used to collect information regarding sociodemographic characteristics, knowledge (eight questions), attitudes (three questions), and practice (three questions). Of the total study participants, 64.31% were female and 95% lived in rural areas. The results showed that the poor knowledge, attitude and practice of the before intervention group improved compared to the after intervention and compared with the control group significantly increased with P < 0.05. Therefore, health education programs to improve awareness and raise KAP about COVID-19 are essential, especially for illiterate people, poor people, and a lack of means to communicate.&nbsp