Exposure assessment of traditional and IPM farmers on using pesticides: A case study at Bang Rieng Sub District, Khuan Nieng District, Songkhla Province

A questionnaire was developed to quantitatively evaluate the exposure to pesticides and to gauge the concentration of organophosphate pesticides such as chlorpyrifos and methyl-parathion while the farmers of Bang Rieng were spraying these pesticides. The results were applied to the exposure assessment and to compare the quantity of exposure to these pesticides between 33 traditional and 40 integrated pest management (IPM) farmers of Bang Rieng. There was a significant difference in the level of exposure between the traditional farmers, who had the average pesticide exposure scores of 58.30 points and the IPM farmers, whose average scores were 53.50 points, (p < 0.015). Concentrations of organophosphate pesticides chlorpyrifos and methyl-parathion were measured. Thirty-three air samples were collected by personal sampling during the period of pesticide spraying. Traditional farmers were exposed to higher levels of the pesticide(s) with a mean concentration of 0.1865 mg/m compared to the IPM farmers who were exposed to a mean pesticide concentration of 0.037 mg/m3. It was estimated that the farmers of Bang Rieng would be exposed to 186-19,616.6 mg of the organophosphatepesticide(s) via inhalation throughout their lifetime (65 years). Moreover, according to the exposure assessment, the traditional farmers exposed to a greater amount of the pesticide(s) via inhalation compared to the IPM farmers

Factors Associated with Pesticide Risk Behaviors among Rice Farmers in Rural Community, Thailand

The need to use large amounts of pesticides has raised environmental health and human health concerns. Several reports reveal that many farmers in Thailand continue to be poisoned through unsafe practices in the use of pesticides. Few studies exist that examine pesticide risk behaviors and beliefs among rice farmers in Thailand. The study objective was to evaluate health beliefs and behaviors associated with pesticide risk behaviors among rice farmers in the Khlong Seven community from March to December 2010. Data collection from 482 rice farmers was completed by observation, in-depth interviews, and focus group discussions. We found the main potential exposure pathways included: take-home exposure; ingestion from food intake, especially vegetables and drinking water; environment risks, especially the proximity of family homes to farms, spray drift areas, and; the most concern stemmed from their practice. Major factors of pesticide poisoning in the Khlong Seven community were the unsafe use of pesticides including erroneous beliefs of farmers about pesticide toxicity, lack of attention to safety precautions, environmental hazards, and information about first aid and antidotes written on the container labels, the use of faulty spraying equipment or lack of proper maintenance of spraying equipment, and wearing protective gear and appropriate clothing during the handling of pesticides. This study concludes that an intervention program is necessary to improve safer pesticide behaviors and to decrease pesticide exposure among rice farmers in Khlong Seven community. Keywords: rice farmers, pesticide exposure, risk behaviors, rural communit

Inhalation Exposure of Organophosphate Pesticides by Vegetable Growers in the Bang-Rieng Subdistrict in Thailand

This study investigated inhalation exposure to organophosphate pesticides (OPPs) and evaluated the associated health risks to vegetable growers living in the Bang-Rieng agricultural community. Air samples were collected by using personal sampling pumps with sorbent tubes placed in the vegetable growers' breathing zone. Samples were collected during both wet and dry seasons. Residues of organophosphate pesticides, that is, chlorpyrifos, dicrotofos, and profenofos, were analyzed from 33 vegetable growers and 17 reference subjects. Results showed that median concentrations of OPPs in air in farm areas were in the range of 0.022–0.056 mg/m3 and air in nonfarm areas in the range of <0.0016–<0.005 mg/m3. The concentration of the three pesticides in the vegetable growers was significantly higher than that of the references during both seasons. The results also indicate that the vegetable growers may be at risk for acute adverse effects via the inhalation of chlorpyrifos and dicrotofos during pesticide application, mixing, loading, and spraying. It is suggested that authorities and the community should implement appropriate strategies concerning risk reduction and risk management

eReefs modelling suggests Trichodesmium may be a major nitrogen source in the Great Barrier Reef

Trichodesmium can fix nitrogen that is later released into the water column. This process may be a major source of ‘new’ nitrogen in the Great Barrier Reef (GBR), but to date this contribution is poorly resolved. We have estimated the seasonal, spatial and annual contributions of Trichodesmium to the annual nitrogen budget of the GBR using the eReefs marine models. Models were run for the interval December 2010 to November 2012. During this period La Niña conditions produced record rainfalls and widespread flooding of GBR catchments. Model outputs suggest nitrogen fixation by Trichodesmium in the GBR (which covers about 348,000 km2) contributes approximately 0.5 MT/yr, exceeding the total average annual riverine nitrogen loads (0.05–0.08 MT/yr). Nitrogen fixation loads are exceeded by riverine loads only if the comparison is restricted to inshore waters and during the wet season. The river pollution is likely to have impacts in freshwater wetlands, mangroves, seagrasses and in-shore coral reefs; while Trichodesmium blooms are likely to be less intense but more widespread and affect offshore coral reefs and other oceanic ecosystems. Phosphorus and iron are suggested to be potential drivers of Trichodesmium growth and nitrogen fixation. This result is provisional but reinforces the need for more detailed assessment and reliable quantification of the annual nitrogen contribution from nitrogen fixation in the GBR and other coastal waters. Such advances will improve understandings of the role of terrestrial nitrogen loads in the GBR and of terrestrial phosphorus and iron loads which can modulate Trichodesmium abundance. These findings will help to broaden the focus of water quality management programmes and support management to improve GBR water quality

Farmworker Exposure to Pesticides: Methodologic Issues for the Collection of Comparable Data

The exposure of migrant and seasonal farmworkers and their families to agricultural and residential pesticides is a continuing public health concern. Pesticide exposure research has been spurred on by the development of sensitive and reliable laboratory techniques that allow the detection of minute amounts of pesticides or pesticide metabolites. The power of research on farmworker pesticide exposure has been limited because of variability in the collection of exposure data, the predictors of exposure considered, the laboratory procedures used in analyzing the exposure, and the measurement of exposure. The Farmworker Pesticide Exposure Comparable Data Conference assembled 25 scientists from diverse disciplinary and organizational backgrounds to develop methodologic consensus in four areas of farmworker pesticide exposure research: environmental exposure assessment, biomarkers, personal and occupational predictors of exposure, and health outcomes of exposure. In this introduction to this mini-monograph, first, we present the rationale for the conference and its organization. Second, we discuss some of the important challenges in conducting farmworker pesticide research, including the definition and size of the farmworker population, problems in communication and access, and the organization of agricultural work. Third, we summarize major findings from each of the conference’s four foci—environmental exposure assessment, biomonitoring, predictors of exposure, and health outcomes of exposure—as well as important laboratory and statistical analysis issues that cross-cut the four foci

A prospective study of cancer risk among Agricultural Health Study farm spouses associated with personal use of organochlorine insecticides

Background: Organochlorine insecticides (OCs) have historically been used worldwide to control insects, although most have now been banned in developed countries. Evidence for an association between OC exposures and cancer predominantly comes from occupational and population based-studies among men. We evaluated the association between the use of specific OCs and cancer among the female spouses of pesticide applicators in the Agricultural Health Study. Methods: At enrollment (1993–1997), spouses of private applicators in the cohort provided information about their own use of pesticides, including seven OCs (aldrin, chlordane, dieldrin, DDT, heptachlor, lindane, and toxaphene), and information on potential confounders. We used Poisson regression to estimate relative risks (RRs) and 95% confidence intervals (CIs) for cancers (n ≥ 3 exposed cases) reported to state cancer registries from enrollment through 2012 (North Carolina) and 2013 (Iowa), and use of the individual OCs, as well as use of any of the specific OCs. Results: Among 28,909 female spouses, 2191 (7.58%) reported ever use of at least one OC, of whom 287 were diagnosed with cancer. Most cancers were not associated with OC use. Risk of glioma was increased among users of at least one OC (Nexposed = 11, RR = 3.52, 95% CI 1.72–7.21) and specifically among lindane users (Nexposed = 3, RR = 4.45, 95% CI 1.36–14.55). Multiple myeloma was associated with chlordane (Nexposed = 6, RR = 2.71, 95% CI 1.12–6.55). Based on 3 exposed cases each, there were also positive associations between pancreatic cancer and lindane, and ER-PR- breast cancer and dieldrin. No other associations with breast cancer were found. Conclusions: Overall, there were some associations with OC use and cancer incidence, however we were limited by the small number of exposed cancer cases. Future research should attempt to expand on these findings by assessing environmental sources of OC exposures, to fully evaluate the role of OC exposures on cancer risk in women

Studying Health Outcomes in Farmworker Populations Exposed to Pesticides

A major goal of studying farmworkers is to better understand how their work environment, including exposure to pesticides, affects their health. Although a number of health conditions have been associated with pesticide exposure, clear linkages have yet to be made between exposure and health effects except in cases of acute pesticide exposure. In this article, we review the most common health end points that have been studied and describe the epidemiologic challenges encountered in studying these health effects of pesticides among farmworkers, including the difficulties in accessing the population and challenges associated with obtaining health end point data. The assessment of neurobehavioral health effects serves as one of the most common and best examples of an approach used to study health outcomes in farmworkers and other populations exposed to pesticides. We review the current limitations in neurobehavioral assessment and strategies to improve these analytical methods. Emerging techniques to improve our assessment of health effects associated with pesticide exposure are reviewed. These techniques, which in most cases have not been applied to farmworker populations, hold promise in our ability to study and understand the relationship between pesticide exposure and a variety of health effects in this population

NUScon: a community-driven platform for quantitative evaluation of nonuniform sampling in NMR

Although the concepts of nonuniform sampling (NUS) and non-Fourier spectral reconstruction in multidimensional NMR began to emerge 4 decades ago (Bodenhausen and Ernst, 1981; Barna and Laue, 1987), it is only relatively recently that NUS has become more commonplace. Advantages of NUS include the ability to tailor experiments to reduce data collection time and to improve spectral quality, whether through detection of closely spaced peaks (i.e., “resolution”) or peaks of weak intensity (i.e., “sensitivity”). Wider adoption of these methods is the result of improvements in computational performance, a growing abundance and flexibility of software, support from NMR spectrometer vendors, and the increased data sampling demands imposed by higher magnetic fields. However, the identification of best practices still remains a significant and unmet challenge. Unlike the discrete Fourier transform, non-Fourier methods used to reconstruct spectra from NUS data are nonlinear, depend on the complexity and nature of the signals, and lack quantitative or formal theory describing their performance. Seemingly subtle algorithmic differences may lead to significant variabilities in spectral qualities and artifacts. A community-based critical assessment of NUS challenge problems has been initiated, called the “Nonuniform Sampling Contest” (NUScon), with the objective of determining best practices for processing and analyzing NUS experiments. We address this objective by constructing challenges from NMR experiments that we inject with synthetic signals, and we process these challenges using workflows submitted by the community. In the initial rounds of NUScon our aim is to establish objective criteria for evaluating the quality of spectral reconstructions. We present here a software package for performing the quantitative analyses, and we present the results from the first two rounds of NUScon. We discuss the challenges that remain and present a roadmap for continued community-driven development with the ultimate aim of providing best practices in this rapidly evolving field. The NUScon software package and all data from evaluating the challenge problems are hosted on the NMRbox platform

Secondary Structure, a Missing Component of Sequence-Based Minimotif Definitions

Minimotifs are short contiguous segments of proteins that have a known biological function. The hundreds of thousands of minimotifs discovered thus far are an important part of the theoretical understanding of the specificity of protein-protein interactions, posttranslational modifications, and signal transduction that occur in cells. However, a longstanding problem is that the different abstractions of the sequence definitions do not accurately capture the specificity, despite decades of effort by many labs. We present evidence that structure is an essential component of minimotif specificity, yet is not used in minimotif definitions. Our analysis of several known minimotifs as case studies, analysis of occurrences of minimotifs in structured and disordered regions of proteins, and review of the literature support a new model for minimotif definitions that includes sequence, structure, and function. © 2012 Sargeant et al