Nonfatal occupational injury among California farm operators

We conducted a population-based telephone survey addressing farm-work-related (FWR) injuries among California farm operators. Of 1947 participants (80.4% response), 135 farm operators reported 160 FWR injuries in the preceding year, yielding a one-year cumulative incidence for any FWR injury of 6.9% (95% CI 5.8%-8.2%), or a mean 8.2 FWR injuries per 100 farmers in the preceding year (95% CI 6.8-9.7). Multiple injury events in the same individual occurred more frequently than predicted by chance. Sprains and strains (29.4%) were the most frequently reported injury and predominantly involved the back. Overexertion represented the most frequent external cause (24.2%), followed by machinery (14.3%), falls (13.0%), and animals (12.4%). Factors associated with FWR injury included white ethnicity (OR 3.19; 95% CI 1.38-7.36), increased annual hours worked on the farm, low levels of administrative work, and increased percentage of time working with livestock. FWR injury experience of California farm operators is comparable with that reported for other agricultural populations. Above-expected frequency of multiple injuries supports involvement of personal or environmental risk factors. Preventive efforts should focus on higher-risk groups and preventing overexertion and muscle strain and injury related to machinery, falls, and animals, especially livestock.     

Eye injury in migrant farm workers and suggested hazard controls

The eyes are a common site of injury in agricultural operations. Identification of the cause of injury is important to inform preventive interventions. The objective of this study was to describe the hazards and mechanisms of acute traumatic injury to the eyes of agricultural workers who are hired in farming operations on a seasonal basis. A review of the literature was performed to summarize the mechanisms of eye injuries in agriculture. Field observations and informal interviews were performed to verify the literature and to determine whether there are eye hazards for farm workers that have not been reported in the literature. Additional mechanisms of injury were elicited, and suggested methods of injury prevention are presented here.     

Minimizing bias in a case-control study of farm injury

We report on our strategies to minimize bias in the FIRM study, a prospective case-control study of risk factors for serious farmwork-related injury. The study base is adult males working on farms in the catchment regions of 14 larger regional hospitals in one Australian state. Cases are identified on presentation to the emergency departments, while age-matched controls are recruited via random telephone survey. Eligibility criteria for cases include a maximum abbreviated injury severity score of at least 2, to minimize the potential for selection bias against those with less severe injuries treated outside the hospital system. An audit at one hospital showed that 93% of eligible patients identified in the electronic surveillance system had been approached regarding participation. Results to date show that 38% of those approached decline to have their contact details made available to researchers. Those who decline are asked to complete two key questions to enable comparison with those who participate. Control recruitment relies on telephoning regional households until an individual from the study base, satisfying the matching criteria, is identified. This process minimizes the potential for selecting against farm workers who may live off-farm. Ninety-four percent of age-matched eligible controls have participated to date. We are testing a dynamic pool of individuals identified as study base members but not matched on the first call to determine its effect on the probabilities of selection. Our strategies appear to be minimizing detection, selection, and response bias, thereby enhancing the validity of the study results.     

Stability study of a sulfadimidine-containing medicated premix and its mixture with farm feed

The objective of this paper was to study the stability of a medicated premix and a medicated farm feed containing sulfadimidine as the active ingredient. The medicated premix is supplied as powdered form and administered orally after mixing with animal feed. The sulfadimidine analytical method described in United States Pharmacopoeia 23 cannot be used to carry out the stability study because of its lack of specificity for different degradation products. Therefore, a high-performance liquid chromatography method was developed to assay sulfadimidine. This method was optimized and validated for the stability study. According to International Committee Harmonization (ICH) guidelines, the samples were stored under long-term testing and accelerated conditions for the stability study of the premix and the medicated farm feed. Sulfadimidine degradation was not detected in either form under any of the conditions studied.     

近红外光谱技术及其在农产品品质分析中的应用

近红外光谱技术是一种高效、快速的现代分析技术,已在很多领域得到广泛应用。文章对近红外光谱分析的技术原理、技术方法、技术特点作了简要介绍,并对其在农产品品质分析中的应用现状和应用前景进行了综述。     

Nature of soil carbohydrate and its association with soil humic substances

The fulvic acid and alkali-soluble polysaccharide fractions of a sandy loam arable soil of the Countesswells series have been subjected to acid hydrolysis or methylation and the products examined by infra-red and NMR spectroscopy, pyrolysis mass spectrometry and chemical analysis. Infra-red and NMR spectroscopy of the polysaccharide fraction indicated that the substance was predominantly carbohydrate, although sugars accounted for less than one-third of the weight by chemical analysis. Pyrolysis mass spectrometry con-firmed the presence of sugars by sugar anhydride formation, but also showed the presence of ‘secondary’ or ‘pseudo’ polysaccharide. The fulvic acid contained only 2–3% sugars by chemical analysis, whereas a much larger carbohydrate component was suggested by physicochemical analyses. Infra-red and pyrolysis mass spectrometry difference spectra for the residues after acid hydrolysis indicated the release of material with some of the characteristics of glycoprotein. Most of the carbohydrate present in the fulvic acid was of the secondary or pseudo polysaccharide type. The hypothesis that the secondary polysaccharide could be a degraded polysaccharide structure in which some sugar residues have been partly transformed to melanoidins by Maillard reaction is explored.     

Effect of age on hospitalized machine-related farm injuries among the Saskatchewan farm population

Machinery-related injuries are the leading cause of fatal and hospitalized injuries on Canadian farms. In Saskatchewan, the proportion of all farm injuries related to farm machinery exceeds that reported for all of Canada. This project examined the relationship between age and various factors associated with farm machine-related injuries in Saskatchewan. A retrospective review of hospital discharge data from the administrative data set of Saskatchewan Health was conducted using external cause of injury codes to identify cases of farm machinery injury that occurred in Saskatchewan during the period April 1, 1990, to March 31, 2000. Log linear estimates of association of various factors in four age groups were derived. There were 1,493 hospitalizations attributed to farm machinery-related injuries. Among the injured cohort, age was a predictor of the rate of injury. Significant association for nature of injury, mechanism of injury, and type of machine varied by age group. These data provide insights for a case-control study of farm machinery-related injuries with the objective of determining personal, environmental, and machine-related factors that are responsible for this serious public health issue.     

农产品光学参数测量的双积分球系统及其应用

为了得到农产品生物组织光学参数,设计了一套双积分球系统实验测量装置。文中描述了其测量原理、系统组成和测量技术,采用650 nm的半导体激光器作为光源,对Intralipid溶液和Evans Blue溶液进行了实际测量,验证了该测量系统的准确性。通过实测,纯牛奶的散射系数为27.719±0.836,吸收系数为0.014±0.001,各向异性因子g=0.846±0.002。通过与其它测量方法对照,相对误差小于5%,该装置能够较准确地获得样品的散射与吸收系数,使之适用于农产品(如果品蔬菜、动物肉、牛奶等)光学参数的测量。     

无公害农产品市场准入及相关对策

本文综合分析了目前国内外主要农产品污染的现状及成因。介绍了国内外无公害农业发展概况、无公害农产品生产技术和无公害农产品质量安全检验标准。在此基础上 ,对我国无公害农业的发展方向、无公害农产品安全优质生产提出了相应对策     

高温胁迫对紫花苜蓿的影响及其适应机制的相关研究

紫花苜蓿是优质的多年生豆科牧草,喜温暖半干旱气候。高温能使其植株生长缓慢、枯萎甚至死亡,病虫害增多,严重影响紫花苜蓿的产量和品质,是限制紫花苜蓿推广利用的一个重要环境因子之一。紫花苜蓿在高温胁迫后,细胞膜流动性、光合作用及呼吸效率等发生改变,产生大量的渗透调节物质、活性氧和热激蛋白等,提高了紫花苜蓿的耐热性,形成了适应高温应激的适应机制。本研究在分析紫花苜蓿特征特性的基础上,从高温对紫花苜蓿的影响、紫花苜蓿适应高温胁迫的机制及其耐热性评价指标的选择和可靠性评价的方法等方面综述了紫花苜蓿耐热性的研究现状,为开展进一步的研究工作提供参考。     

Iodine deficiency and its association with intelligence quotient in schoolchildren from Colima, Mexico

OBJECTIVE: To determine the prevalence of iodine deficiency, its causes and its association with intelligence quotient (IQ) in Mexican schoolchildren. DESIGN: Cross-sectional analytical study, in which determinations of thyroid gland size, urinary iodine excretion, IQ, iron nutritional status, physical anthropometry, family consumption of goitrogenic foods, type/origin and iodine saturation of salt consumed at home and coliform organisms in drinking water were performed, and the association of each variable with IQ scores was evaluated by multiple regression analyses. SETTING: Municipality of Cuauhtémoc, in Colima, Mexico (altitude: 600-2700 m above sea level). Sea salt is extracted manually nearby and often used for human consumption. Goitre remains present in the region despite over half a century of mandatory salt iodination in the country. SUBJECTS: Three hundred and three children, similar proportions of boys and girls, mean age 9.3 years, randomly selected from 19 public elementary schools. RESULTS: Overall goitre rate was 21.4%; low urinary iodine excretion was found in 19.5% of the children, high urinary iodine excretion in 32.0%. IQ scores were transformed into percentile values, with the following categorisation: < or = P5 (low IQ), 48.5%; > P5 to < or = P25 (below average), 24.2%; > P25 to < P75 (average), 18.8%; > or = P75 to < P95 (above average), 3.6%; > or = P95 (high IQ), 4.9%. Ninety-two per cent of the population used iodinated salt, but deficient iodine saturation (<50 ppm) was found in 86.8% of salt samples. The main goitrogenic foods consumed were peanuts (by 31.5% of the sample), cabbage (30.1%), broccoli (27.7%) and cauliflower (25.7%). Median counts of coliform organisms (colony-forming units/100 ml of drinking water) were: 207.5 (well water), 151 (cisterns), 52 (private homes), 25 (elementary schools) and 12 (kindergartens). Moderate iodine deficiency was associated (P < 0.05) with a 4.26 times higher risk of low IQ. CONCLUSIONS: There is a perturbing negative impact of these findings on human capital acquisition for the region and the country. More attention is needed to ensure effective salt iodination processes, particularly in regions where goitrogens may contribute to the negative effects of iodine deficiency on the intellectual development of children.     

干旱生境中VA菌根对宿主植物的影响及其机制

试验研究证明VA菌根可以影响宿主植物的水分关系。文章综述了VA菌根在干旱胁迫条件下对宿主植物形态、代谢、渗透适应的影响以及VA菌根可能提高宿主抗/耐旱性的机制。文章认为,VA菌根有利于宿主植物抗/耐旱性的作用是由于物理的、化学的、生理的、细胞的综合作用的结果。     

Tractor driving among kentucky farm youth: results from the farm family health and hazard surveillance project

This article documents the extent of children's involvement in tractor operations among a representative sample of Kentucky children living and working on family farms. Specifically, we describe children's exposures to tractor-related work activities, profile their use of the tractor (number of days worked), and assess compliance with generally recommended safety measures, such as using tractors equipped with ROPS (rollover protective structures), avoiding riding as passengers on tractors, and operating tractors on public roadways. Data for this study were collected in 1994 and 1995 as part of the NIOSH-sponsored Farm Family Health and Hazard Surveillance Project (FFHHSP). Despite recognition in the health and safety community of the hazards associated with operating tractors without ROPS on public roadways and with extra riders, these practices remain common among youth on Kentucky farms. Farms with annual incomes greater than $10,000, particularly with livestock commodities, appear to use youth for a greater number of days of tractor operation than other farms. Such farms may be an appropriate target for intervention.     

Effect of garlic oil on neutrophil infiltration in the small intestine of endotoxin-injected rats and its association with levels of soluble and cellular adhesion molecules

Garlic ( Allium sativum ) possesses anti-inflammatory effects. This study investigated the effects of garlic oil on endotoxin-induced neutrophil infiltration in the small intestine. Wistar rats received by gavage 10, 50, or 100 mg/kg body wt garlic oil (GO) or the vehicle (corn oil; 2 mL/kg body wt) every other day for 2 weeks before being injected with endotoxin (ip, 5 mg/kg body wt). Control rats were administered corn oil and injected with sterile saline. Blood samples for the measurement of soluble adhesion molecules were collected at various time points after injection, and all other samples were collected 18 h after injection. The 10 and 50 mg/kg doses suppressed endotoxin-induced neutrophilia, serum levels of sL-selectin and sICAM-1, cellular CD11b on neutrophils, intestinal ICAM-1 content, and neutrophil infiltration (P < 0.05). The 100 mg/kg dose significantly lowered local ICAM-1 and cellular CD11b on neutrophils (P < 0.05) but did not have a beneficial effect on neutrophil infiltration. In addition, 100 mg/kg of GO worsened the elevation of the local TNF-α level and neutrophilia. Appropriate doses of garlic oil have a preventive effect on endotoxin-induced neutrophil infiltration and damage to the small intestine.     

Outbreak of occupational campylobacteriosis associated with a pheasant farm

A cluster of campylobacteriosis cases occurred at a pheasant farm in rural Wyoming during the summer of 2000. This study examined the potential causes of the outbreak. A cohort study of all farm workers was conducted to assess foodborne and occupational exposures at the facility. Eight of fifteen workers (53%) became ill, and four were stool-culture positive for Campylobacter jejuni. High attack rates were noted among workers who had direct contact with pheasant feces and first-time workers at the farm. This investigation suggests an association between campylobacteriosis and occupational animal exposure to pheasants. Enhanced educational efforts targeting occupations with direct animal contact are critical, particularly in rural communities.     

悬挂农具对电液悬挂系统拖拉机振动的影响

悬挂农具设备的拖拉机在行驶过程中的振动会加剧,有时甚至产生很大的俯仰运动。为了研究悬挂农具的存在对拖拉机振动特性的影响,该文在对拖拉机进行运动学和动力学分析的同时,首次详细分析了悬挂机构的运动及受力情况,从而建立了带有悬挂农具的大功率拖拉机整机振动数学模型;用Matlab仿真了拖拉机受到条形水泥障碍激励时的振动情况。研究表明:农具的存在使拖拉机前轮动载系数由O.26增大到0.55;空载拖拉机垂直振动频率为3 Hz,带农具的拖拉机垂直振动频率为2.5 Hz;农具的存在使得拖拉机的俯仰振动显著增加,频率为4.8 Hz;由于悬挂系统的运动与拖拉机机体振动的非线性耦合,一定条件下会表现出频率为10~15 Hz的第3振型的振动;农具的振动使得电液悬挂系统下拉杆铰接点处的力发生相应变化,其垂直分量的大小与农具质心垂直加速度之间存在较好的线性关系。仿真结果与试验结果相吻合,验证了所建数学模型的正确性。所得到的上述结论为拖拉机主动减振控制提供了理论依据。     

The effect of cobalt stress on growth and physiological traits and its association with cobalt accumulation in barley genotypes differing in cobalt tolerance

Cobalt (Co) is beneficial for legume plants and not an essential element for most plants. There is no sufficient information about the effect of Co stress on barley growth. The current experiment was carried out to investigate the effects of different Co levels (25, 50, 75, and 100 µM) on growth and physiological traits of three barley genotypes (B325, J36, and B340) differing in Co tolerance. The results showed that Co stress inhibited plant growth, decreased chlorophyll content and photosynthetic rate, and enhanced oxidative stress. However, the effects differed among genotypes, with B325 and B340 being the most and the least affected, respectively. Co stress caused decrease and increase of manganese (Mn) and phosphorus (P) concentrations in both roots and shoots, respectively; iron (Fe) concentration had little change in shoots and a significant decrease in roots. The current results showed a close association of Co tolerance and its accumulation in plant tissues.     

基于BEPS生态模型模拟农田土壤水分动态

为了提高农田水分动态的模拟精度,以提高农田水管理的效率,该文研究验证了BEPS机理生态模型模拟季风气候区农田土壤水分的能力,分析了导致模型误差的原因。结果表明,BEPS模型能较好地模拟江苏省徐州农业气象试验站冬小麦生长季根层土壤水分动态,2000－2004年模拟结果与实际观测值的决定系数R2的范围在0.1339～0.9225之间,均方根误差和平均绝对误差分别在0.026113～0.06317和0.0232～0.0525之间。土壤水分饱和传导率和决定土壤水分传导率变化的参数对模拟结果有较大影响。模拟结果的可靠性及其对土壤水分饱和传导率和决定土壤水分传导率变化的参数的敏感性与降水和土壤含水率条件有关,当降水长期偏少、土壤含水率下降时,模拟的上层土壤含水率会较观测数据偏低,对2个参数的敏感性上升。