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Pymetrozine has replaced toxic organophosphate pesticides previously used for controlling pests of rice crops in China. Existing data on its environmental behavior are usually related to studies on artificial plots that do not adequately address the natural dynamics and residues in actual field conditions. Therefore, studies under field conditions were carried out to investigate the natural dynamics and residues of pymetrozine in two typical rice-growing areas in China - Hunan and Guangxi provinces. Samples of paddy soil and water were collected in relation to spraying events in the study areas. The quick, easy, cheap, effective, rugged and safe (QuEChERS) method was used to extract pymetrozine residues from the samples by a Waters ACQUITY UPLC (Milford, MA, USA) system interfaced with a triple-quadrupole mass spectrometer (Xevo TQ-D, Waters Corp., USA). The initial deposition of pymetrozine in paddy soils was higher than in paddy waters in both areas. The decay of pymetrozine followed an exponential trend consistent with the first order kinetics. The half-life of pymetrozine in paddy water was determined to be 3.0 and 3.8 days, whereas the half-life in soil was 3.8 and 3.5 days in the Guangxi and Hunan samples, respectively. The decline rates of pymetrozine in paddy soil and paddy water in this field study were faster than those conducted under non-field conditions reported in previous studies. Compared to other pesticides used in China as reported in previous studies, the environmental persistence of pymetrozine in both paddy water and soils in Guangxi and Hunan provinces is very low. This has important implications for the use of pymetrozine in agricultural systems globally.

Chlorpyrifos is one of the most widely used organophosphate pesticides and has a record of adverse effects on applicators. Assessment of exposure to chlorpyrifos based on its urinary metabolite, 3,5,6-trichloro-2-pyridinol (TCP), is considered as the most accurate. However, urine sampling can be difficult, and the laboratory analytical procedures involved are complex and expensive. A simpler approach for assessing pesticide exposure among applicators is the whole-body dermal dosimetry method, but this needs validation. The objective of this study was to compare chlorpyrifos exposure estimates obtained separately with the urinary TCP and the whole-body dermal dosimetry methods from applicators. Exposure estimates from the whole-body dermal dosimetry method (5–29 μg/kg/day) showed less variation than those from the urinary TCP method (1–71 μg/kg/day), but both were in close agreement at the mean level (16 μg/kg/day and 15 μg/kg/day, respectively). The whole-body dermal dosimetry method is therefore valid for providing estimates of the typical levels of pesticide exposure among applicators in situations where the urinary TCP method cannot be applied.

The concentration level related to toxicities of trace elements in drinking water, rice, wheat flour, and their associated negative impacts on human health have become an emergent issue in China. Because Xinjiang is the largest province in China with the majority of arable pasture land available for cultivation, it is important to analyze the concentrations of trace elements in relation to their toxicities in water, rice, and wheat flour and to investigate the health risk differences between agricultural and pastoral areas in Bay County, Xinjiang. The study results showed that (1) metal concentrations from drinking water, rice, and wheat flour were within the permissible limits; (2) concentration levels of trace elements and their total risk from drinking water and rice were higher in the agricultural areas than those in the pastoral areas, whereas concentration levels of trace elements and their total risk from wheat flour were higher in the pastoral areas than those in the agricultural areas; (3) the concentration level of the trace elements in rice were higher than in the wheat flour, but the risk from the wheat flour was higher than the risk from rice; (4) total non-cancer risk from the flour (HIf) in both areas exceeded the respective safe reference doses; (5) total cancer risk from the wheat flour, rice, and water exceeded the safety limit (1 × 10−4); (6) for the exposed population, arsenic was suggested as the most evident pollutant leading to carcinogenic concerns regarding the water, rice, and wheat flour; (7) the risk index from the wheat flour made up the highest percentage both in the total cancer risk and the non-cancer risk, followed by rice and then water; and (8) the human health risk was attributed to influence from the local environment in the agriculture areas, while it was attributed to the external environment in the pastoral areas.

This study aimed to examine the effectiveness of Human Immunodeficiency Virus (HIV)-assisted smartphone applications in the treatment of HIV/AIDS patients in Vietnam. A cross-sectional study was performed in two urban outpatient clinics in Hanoi from May to December 2019. A simple random sampling method and a structured questionnaire were used to recruit 495 eligible participants and to collect data. Multivariable modified Poisson regression and multivariable linear regression models were employed to investigate the factors associated with the willingness to pay (WTP) and amount of money patients were willing to pay. Approximately 82.8% of respondents were willing to pay for the hypothetical applications, with the mean amount the participants were willing to pay of Vietnam Dong (VND) 72,100/month. Marital status (separate/divorced/widow: Odds ratio (OR) = 1.28, 95% confidence interval (CI) = (1.09, 1.50) and having spouse/partner: OR = 1.18, 95% CI = (1.03, 1.36)) and using health services (OR = 1.03, 95% CI = (1.01, 1.04)) were positively associated with nominating they would be WTP for the app, whereas the duration of antiretroviral treatment (ART) (OR = 0.98, 95% CI = (0.96, 0.99)) had a negative association. The frequency of using health services (β = 0.04, 95% CI = (−0.07, −0.01)) was negatively associated with the amount of WTP. High levels of WTP revealed the feasibility of implementing smartphone-based apps for HIV treatment. This study implied the necessity to consider a co-payment system to reach populations who were in need but where such applications may be unaffordable in lieu of other treatment-associated expenses. Developers also need to pay attention to privacy features to attract single people living with HIV/AIDS and additional measures to initiate people with a long duration on ART into using the applications.

Health personnel and community workers are at the front line of the COVID-19 emergency response and need to be equipped with adequate knowledge related to epidemics for an effective response. This study aimed to identify the coverage of COVID-19 health information via different sources accessed by health workers and community workers in Vietnam. A cross-sectional study using a web-based survey was carried out from January to February 2020 in Vietnam. Respondent-driven sampling (RDS) was used for recruiting participants. We utilized the exploratory factor analysis (EFA) to examine the construct validity of the questionnaire. A higher percentage of participants knew about &ldquo, Clinical and pathogen characteristics of COVID-19&rdquo, compared to &ldquo, Regulations and policies related to COVID-19&rdquo, The percentage of participants accessing the information on &ldquo, Guidelines and policies on prevention and control of COVID-19&rdquo, was the lowest, especially among medical students. &ldquo, Mass media and peer-educators&rdquo, channels had a higher score of accessing COVID-19 information, compared to &ldquo, Organizations/ agencies/ associations&rdquo, sources. Participants consumed most of their COVID-19 information via &ldquo, Internet, online newspapers, social networks&rdquo, Our findings indicate an urgency to re-design training programs and communication activities for a more effective dissemination of information related to the COVID-19 epidemic or epidemics in general.

Climate-related disasters are increasing across the globe, but their adverse health impacts are unevenly distributed. The people most severely affected tend to be from socio-economically disadvantaged, vulnerable populations, who have high exposure to risk conditions and insufficient adaptive capacity. Despite the increasing health impacts of climate change and disaster risks felt in Asian countries such as China, Indonesia and Vietnam, there are few attempts to access and translate literature and evidence on climate-related disasters and adaptation activities from non-English speaking countries. Conducted by a multi-country project team, this review aims to better understand the current literature and to study gaps in these three countries through an extensive search of literature, in English, Chinese, Indonesian and Vietnamese. Through a systematic review process a total of 298 studies out of 10,139 were included in this study. Key findings confirm that all three countries have experienced increasing climate-related disasters with their associated health impacts, and that adaptation strategies are urgently needed to reduce the risk and vulnerability of the most affected populations. Future studies should consider conducting vulnerability assessments to inform translational research on developing effective adaptation strategies. Authors commented that a common challenge they found was the shortterm nature of disaster response mechanisms, and the lack of long-term investment and policy support for capacity building and multi-sectoral collaborative research that address the needs of populations vulnerable to climate-related disasters. Thus, to better prepare for future disasters, it is vital that governments and international agencies prioritize funding policies to fill this gap.

s The study presents a cross-sectional analysis via a web-based survey to assess the awareness and experiences of Vietnamese health professionals and community workers on climate and epidemic changes and their impacts on society. Health professionals, medical students, and community workers were included in the survey. Factor analysis was used to explore the construct validity of measures, and Multivariable Tobit regression models were used to examine associated factors with awareness about climate and epidemic changes and impacts on society. Results showed that the awareness of participants about climate and epidemic changes was moderately-low, while the awareness about the impacts on society were moderately high. Community workers show higher awareness of climate and epidemic changes compared to health professionals. People working in provincial levels had a lower score (Coef. = -0.64, 95%CI = −1.19 to −0.09) than those working in central level. Compared to Northern participants, those living in Central and Southern regions have lower awareness scores regarding “Changes in weather and epidemics” and “Changes in the environment” compared to Northern people. The higher awareness about climate and epidemic changes were found to be correlated with the higher awareness of “Impacts on health, society and economy” and “Impact on individuals and families”. Community workers scored lower in “Impact on individuals and families” compared to health professionals (Coef.-0.75; 95%CI = −1.34 to −0.16). This study emphasized the vulnerabilities of Vietnamese communities to epidemics and climate change. It suggests the involvements of intersectoral taskforces in the preparedness and responses to climate change and epidemics.

Chlorpyrifos is a neurotoxic insecticide that is widely used in the agricultural sector of Ghana. The main objective of this study was to evaluate the levels of chlorpyrifos exposure and health risk among applicators (n = 21) on irrigated rice farms in Ghana, based on a typical application event. Pre- and post-application urine samples (24-h) were collected from the applicators and analysed for 3,5,6-trichloro-2-pyridinol (TCP), using LC-MS/MS. The levels of chlorpyrifos-absorbed dose with the applicators were estimated from the urinary TCP levels. Prior to application, the median absorbed dose of chlorpyrifos (background exposure) with the applicators was 0.2 μg/kg/day (range 0.05 to 2 μg/kg/day). Following application, the median absorbed dose of chlorpyrifos (application exposure) increased 30-fold to 6 μg/kg/day (range 0.7 to 74 μg/kg/day). The mean elimination half-life (t1/2) of chlorpyrifos was calculated to be 50 h. Hazard quotient (HQ) values (HQ > 1) obtained with the chronic (10 μg/kg/day) and acute (100 μg/kg/day) guideline values of the WHO suggested no risk of chronic or acute health effects, respectively, among both the median and 5% highly exposed groups. However, HQ values (HQ > 1) obtained with the chronic (0.3 μg/kg/day) and acute (5 μg/kg/day) guideline values of the USEPA suggested risk of chronic and acute health effects, respectively, among both the median and 5% highly exposed groups. The quantity of chlorpyrifos formulation applied, spraying duration, and the number of spray tanks applied significantly correlated with the absorbed dose levels of chlorpyrifos from application exposure. Therefore, these factors suggest means to reduce exposure and consequent health risk among the applicators.

Generally, there is limited information on pesticide absorbed dose levels and health risk attributable to the dermal route of exposure among applicators. The objective of this study was to evaluate the absorbed dose levels and consequent health risk from dermal exposure to chlorpyrifos among applicators on rice farms in Ghana. The whole-body dosimetry technique was used to capture chlorpyrifos residues penetrating the applicators' clothing and reaching their skin, as well as residues reaching uncovered body areas of the applicators. Acute (ADDD) and chronic (LADDD) absorbed dose levels of chlorpyrifos were estimated from the residues and plotted as cumulative probability distributions. Health risk from chlorpyrifos exposure was characterized using the Hazard Quotient (HQ) technique. Three of the four acute exposure guideline values used in the study indicated that applicators, represented by the median-exposed (ADDD, 15 μg/kg/day) and the 5% - highly exposed (ADDD, 27 μg/kg/day) groups were at high risk of acute adverse health effects due to chlorpyrifos exposure, with HQ values ranging from 1.5 to 5 and 2.7 to 9, respectively. Regarding chronic adverse health effects, none of the guideline values suggested risk among the median-exposed group (LADDD, 0.3 μg/kg/day), with HQ values ranging from 0.03 to 1. However, two of the chronic exposure guideline values suggested that the 5%- highly exposed group (LADDD, 0.6 μg/kg/day) may be adversely affected, with HQ values ranging from 1.2 to 2. These findings highlight the importance of the dermal route as a major pesticide exposure pathway and suggest possible exposure minimization strategies.

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. Materials and Method. 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.

Studies evaluating dermal exposure to pesticides among applicators in tropical countries have largely been conducted using the patch dosimetry and hand wiping/washing techniques. This study used the more accurate whole-body dosimetry technique to evaluate dermal exposure to chlorpyrifos among applicators on rice farms in Ghana. The exposure levels were plotted as Cumulative Probability Distribution (CPD). Total Dermal Exposure (TDE) of chlorpyrifos among the median exposed and the 5% highly exposed groups during a spray event were 24 mg and 48 mg, respectively. When these were converted as a percentage of the quantity of active ingredient applied (Unit Exposure, UE), UE values of 0.03% and 0.06% were found among the median exposed and the 5% highly exposed groups, respectively. Overall, the hands were the most contaminated anatomical regions of the applicators, both in terms of proportion of TDE (39%) and skin loading (13 μg/cm2). Also, the lower anatomical region was more contaminated (82% of TDE) compared to the upper anatomical region (18% of TDE). The levels of chlorpyrifos TDE among the applicators were found to be influenced by the quantity of insecticide applied and the height of the crops sprayed (p

Various methods for risk characterization have been developed using probabilistic approaches. Data on Vietnamese farmers are available for the comparison of outcomes for risk characterization using different probabilistic methods. This article addresses the health risk characterization of chlorpyrifos using epidemiological dose-response data and probabilistic techniques obtained from a case study with rice farmers in Vietnam. Urine samples were collected from farmers and analyzed for trichloropyridinol (TCP), which was converted into absorbed daily dose of chlorpyrifos. Adverse health response doses due to chlorpyrifos exposure were collected from epidemiological studies to develop dose-adverse health response relationships. The health risk of chlorpyrifos was quantified using hazard quotient (HQ), Monte Carlo simulation (MCS), and overall risk probability (ORP) methods. With baseline (prior to pesticide spraying) and lifetime exposure levels (over a lifetime of pesticide spraying events), the HQ ranged from 0.06 to 7.1. The MCS method indicated less than 0.05% of the population would be affected while the ORP method indicated that less than 1.5% of the population would be adversely affected. With postapplication exposure levels, the HQ ranged from 1 to 32.5. The risk calculated by the MCS method was that 29% of the population would be affected, and the risk calculated by ORP method was 33%. The MCS and ORP methods have advantages in risk characterization due to use of the full distribution of data exposure as well as dose response, whereas HQ methods only used the exposure data distribution. These evaluations indicated that single-event spraying is likely to have adverse effects on Vietnamese rice farmers.

Various methods for risk characterization have been developed using probabilistic approaches. Data on Vietnamese farmers are available for the comparison of outcomes for risk characterization using different probabilistic methods. This article addresses the health risk characterization of chlorpyrifos using epidemiological dose-response data and probabilistic techniques obtained from a case study with rice farmers in Vietnam. Urine samples were collected from farmers and analyzed for trichloropyridinol (TCP), which was converted into absorbed daily dose of chlorpyrifos. Adverse health response doses due to chlorpyrifos exposure were collected from epidemiological studies to develop dose-adverse health response relationships. The health risk of chlorpyrifos was quantified using hazard quotient (HQ), Monte Carlo simulation (MCS), and overall risk probability (ORP) methods. With baseline (prior to pesticide spraying) and lifetime exposure levels (over a lifetime of pesticide spraying events), the HQ ranged from 0.06 to 7.1. The MCS method indicated less than 0.05% of the population would be affected while the ORP method indicated that less than 1.5% of the population would be adversely affected. With postapplication exposure levels, the HQ ranged from 1 to 32.5. The risk calculated by the MCS method was that 29% of the population would be affected, and the risk calculated by ORP method was 33%. The MCS and ORP methods have advantages in risk characterization due to use of the full distribution of data exposure as well as dose response, whereas HQ methods only used the exposure data distribution. These evaluations indicated that single-event spraying is likely to have adverse effects on Vietnamese rice farmers.

Volatile aromatic hydrocarbons (VAHs: benzene, toluene, ethylbenzene, mp-xylene, o-xylene, styrene, naphthalene) in residential indoor air in Brisbane, Australia were measured in 32 houses. The total VAHs (TVAHs) levels ranged between 2 and 137μg/m(3) and were lower than the most of the houses in the literature data. The VAHs were believed to originate from heat insulation systems, building material products as well motor vehicles but naphthalene and styrene originated from other sources. Internal garages had concentrations which are higher than the indoor air by 25-50% due to the presence of motor vehicles and may be a major source of indoor VAHs. However indoor concentrations are higher than that in the outdoor ambient air. The age of the house was found to be negatively related to VAHs concentrations in the houses with the half-life of TVAH at approximately 13years. The concentration levels of benzene, toluene, ethylbenzene and styrene are well below the guideline values set by agencies from Hong Kong, Japan, Germany and the WHO while the concentration level of naphthalene in one house exceeded the guideline value from Germany.

This analysis of data from the Household Injury Survey conducted in Viet Nam in 2004-2005 sought to characterize the patterns of work-related injuries in Viet Nam and to determine whether self-employed and artisanal workers had higher rates of injuries than formally employed workers. The annual incidence rate of work-related injuries in Viet Nam was 7.06 per 1,000 person-years. Daily alcohol consumption was strongly associated with work-related injuries. The highest burden of injuries was among farmers. Mechanical forces were the most common mechanism of injury. Self-employed workers had a rate of work-related injuries 26% higher than that of formally employed workers. Self-employed workers were younger, less educated, and more likely to be male. This population-based survey showed substantial underreporting of occupational injuries by existing surveillance mechanisms, which focus on formally employed workers. Priorities for future work include developing an integrated surveillance system for injuries and implementing further needs assessments to improve the prevention of occupational injuries.