Protecting young workers in agriculture: participation in tractor certification training.

Tractor-related injuries among youth are an important public health problem. The major objectives of this study were to (1) provide a rigorous estimate of the number of youth operating tractors in Ohio and (2) assess the extent to which these youth are participating in federally mandated tractor safety training. A self-administered questionnaire was completed by approximately 4,000 students ages 14 or 15 years who were enrolled in a stratified cluster sample of 99 Ohio schools. Almost one-third of the youth (30%) reported having operated tractors, with 19% having operated a tractor on a farm not owned by a parent or guardian. More than half of the youth (52%) reported having operated a tractor and/or other hazardous machinery, with 25% having operated the machinery on a farm not owned or operated by a parent or guardian. Extrapolating from 4-H records and Ohio census data, fewer than 1% of the youth who are operating tractors or other hazardous machinery have participated in tractor certification training. Increasing participation in mandated training may be an important step in protecting the health of our nation's young agricultural workers.

Self-reported symptoms of neurotoxicity and agricultural injuries among Ohio cash-grain farmers.

BACKGROUND: In 1993, the Ohio Farm Family Health and Hazard Surveillance Program (OFFHHSP) was initiated to assess the health status of cash-grain farmers and their families. The objective of this study was to examine the postulated relationship between symptoms of neurotoxicity and risk of agriculture-related injury among Ohio cash-grain farmers. METHODS: A reanalysis of the data from a previously published case-control study of cash-grain farmers [Crawford et al. (1998) Am J Ind Med 34:588-599] was performed. The Principal Operator (PO) of each farm was asked to complete a self-administered questionnaire which included items about injuries experienced during the past year. A section of the questionnaire contained a 24-item instrument ("Q24") that queried symptoms of neurotoxicity experienced during the previous 12 months. Design-based multiple logistic regression analyses were conducted to evaluate associations between neuropsychological subsets ("domains") of the 24-item instrument and injury risk among the white male POs (who accounted for >99% of all POs). RESULTS: Significantly elevated odds ratios (ORs) were found in 8 of 11 domains. POs answering in the affirmative to the single item "Have you been bothered by lack of coordination or loss of balance?" were 3.12 times more likely to have reported an injury than POs responding negatively (95% CI 1.68-5.81). CONCLUSIONS: Farmers with higher scores on several Q24 domains, and for particular questionnaire items, appear to be at increased risk of agricultural injury.

Prevalence of ROPS--equipped tractors and farm/farmer characteristics.

Data were collected on tractor safety status and the prevalence of ROPS as part of the Ohio Farm Family Health and Hazard Surveillance Program (FFHHSP) "walk-around" hazard assessments of cash grain farms in central Ohio. Principal operator (PO) characteristics thought a priori to have a possible association with ROPS utilization included age, education, percent time spent farming, total years in agriculture, and previous training in occupational injury prevention. Farm characteristics of interest were farm size, acres of cropland in use, sales value during the past 12 months, and current number of farm workers. Descriptive and logistic regression analyses were conducted to evaluate potential associations between these factors and ROPS utilization patterns. Of 1,044 tractors encountered on 306 farms, 359 (34.4%) were equipped with ROPS, 29 (9.5%) had nothing but ROPS-equipped tractors, and 117 (38.2%) did not have any ROPS-equipped tractors. The absence/presence of ROPS-equipped tractors in our sample was found to vary by several factors, and over a wide range. Results of invariable logistic regression analyses (excluding the relatively small number of tractors manufactured after 1985) indicated that younger POs with at least a high school education who spent more than half their time working in agriculture, employed three or more workers, had 500 or more acres of total farm land and cropland in use, and had a 12-month sales value exceeding $250,000 were more likely to have at least one ROPS-equipped tractor on their farms. However, time spent farming, number of workers, and the 12-month sales value were not strongly predictive in multivariable models. Although more than 20% of the POs in our sample reported having had training in occupational injury prevention, this factor had essentially no value in predicting the absence/presence of ROPS-equipped tractors on their farms. The results of this study illustrate the need for interventions to encourage ROPS retrofitting that target POs with less education and who work on smaller and less productive farms. However, the low overall ROPS utilization rates suggest that all farmers could benefit from intervention efforts.

Agricultural hazard data from a population-based survey of cash grain farms: Ohio observations.

In response to congressional concerns, the National Institute for Occupational Safety and Health (NIOSH) initiated a multistate agricultural surveillance effort in 1990. The Farm Family Health and Hazard Surveillance (FFHHS) program involved separate population-based surveillance efforts by six state agencies or universities which gathered health and hazard data on farm operators and farm families. The results of the Ohio program are presented as an example of the data collection capabilities developed during the course of this project, which include the application of these data in documenting the prevalence of specific agricultural occupational hazards as well as the current attitudes of agricultural operators toward control and elimination of safety and health hazards. Specifically, three operationally defined areas of hazard audit (Structures, Landscape, and Mobile Equipment) are examined for the prevalence of such safety hazards as potential electrical shock, slippery or badly maintained walkways, inadequate chemical and fuel storage, and missing farm equipment moving-part guards. Questionnaire survey response examples are presented as an indication of farm operator attitudes toward safety and health training, on-site professional service access, and use of personal protective equipment. Current plans for data use and distribution, and the potential applications of the data as an occupational safety and health tool are also discussed.

Prevalence of chronic respiratory symptoms among Ohio cash grain farmers.

BACKGROUND: The prevalence of chronic cough, chronic phlegm, dyspnea, and non-cold wheeze was estimated from a mixed-mode survey of Ohio cash grain farmers in 1993. METHODS: Personal characteristics of the principal operators (POs) such as age and cigarette smoking, in addition to selected farm characteristics and relevant medical and work history factors potentially associated with both exposure to respiratory irritants and subsequent respiratory symptoms were considered. RESULTS: The overall design-adjusted prevalences (and the corresponding 95% confidence intervals (CIs) were: 9.4% (7.6-11.1%) for chronic cough, 10.8% (9.0-12.6%) for chronic phlegm, 16.2% (14.1-18.3%) for dyspnea, and 8.1% (6.4-9.8%) for non-cold wheeze. In univariate and multivariate analyses, smoking status was found, not surprisingly, to be the strongest predictor of increased symptom prevalence compared to all other factors. Other non-occupational factors found associated with increased symptom prevalence include age (cough, phlegm, dyspnea) and pet allergy (non-cold wheeze). Occupational factors found at least weakly associated with increased symptom prevalence include lifetime hours of cab tractor operation (cough); percent time spent farming (phlegm); having livestock other than cattle, cows, and calves (dyspnea); acres of corn for silage or green chop (cough); acres of alfalfa hay (non-cold wheeze); and personal involvement with pesticides (cough). CONCLUSIONS: Symptom prevalences reported here are consistent with previous findings from studies of other groups of farmers. Results pertaining to factors found associated with symptom prevalences should be interpreted in light of several sources of potential bias.

A cross-sectional case control study of work-related injuries among Ohio farmers.

The agricultural industry has consistently been ranked among the most hazardous in the U.S. To date, few analytic studies of occupational injury among farm operators and workers have been conducted. A case control study was undertaken to investigate risk factors for agricultural work-related injury among Ohio farm operators. Cases were selected from among 1,793 respondents to a questionnaire administered during the first phase of the NIOSH-sponsored Ohio Farm Family Health and Hazard Study (OFFHHS). Analysis consisted of description of the injury experience of the sample as a whole, followed by logistic estimation of prevalence odds ratios (pORs) measuring the effect of potential risk factors on injury risk. The case series consisted of 90 white male principal operators (POs) injured doing farm work in the 12 months prior to questionnaire completion. Controls consisted of 1,475 white male POs who reported no injuries. The overall rate of injury was 5 per 100 person-years. The most notable result is the relationship between self-reported neurotoxic symptoms and injury, suggesting those with more reported symptoms were at greater risk of injury. The crude OR, when compared to the reference score of < or = 27, increased from 1.74 (95% CI = 0.60-5.09) in the 28-30 category, to 1.89 (95% CI = 0.71-5.03) in the 31-35 category, to 2.96 (95% CI = 1.10-7.96) in the highest category of test score. The P value for trend was 0.0218. These associations largely persisted after controlling for potential confounders with multiple logistic regression. Risk was inversely related to age. The results show marked increases in risk of injury associated with farmers younger than 30 and increased severity of self-reported neurological symptoms, controlling for potential confounding.

Multiple regions of p45 NF-E2 are required for beta-globin gene expression in erythroid cells.

Regulated expression of genes in the beta-globin cluster depends upon sequences located between 5 and 20 kb upstream of the epsilon gene, known as the locus control region (LCR). beta-Globin expression in murine erythroleukemia (MEL) cells depends on NF-E2, a transcription factor which binds to enhancer sequences in the LCR. To gain insight into the mechanism of globin gene activation by NF-E2, an NF-E2 null MEL cell line was used to map regions of NF-E2 required for beta-globin expression. Within the transactivation domain, two discrete proline-rich regions were required for rescue of beta-globin expression. The first was located at the N-terminus of NF-E2, while the second was located N-terminal of the cap 'n collar (CNC) domain. Other proline-rich sequences were dispensable, indicating that proline content per se does not determine NF-E2 activity. Mutations within the conserved CNC domain markedly diminished rescue of beta-globin expression. This domain was required, in addition to the basic leucine zipper domain, for DNA binding activity. The requirement for discrete proline-rich sequences within the transactivation domain suggests that globin gene expression in MEL cells depends on specific interactions between NF-E2 and downstream effector molecules.

Insulin and IGE-1 receptors in a human intestinal adenocarcinoma cell line (CACO-2): regulation of Na+ glucose transport across the brush border.

Both insulin and IGF-1 receptors are present in intestinal mucosal cells, although their role in this tissue is unclear. We have characterized these receptors in a human adenocarcinoma cell line, Caco-2, and examined their role in the regulation of glucose transport and absorption in these cells. The Caco-2 cells demonstrated specific insulin and IGF-1 receptors. They also bound cytochalasin B, suggesting the presence of a glucose transporter-like protein. When grown on membranes, the Caco-2 cells formed columnar, bipolar cells with tight junctions. The monolayer selectively transported D-glucose and methyl-D-glucose, with complete exclusion of L-glucose, D-mannitol and inulin. The absorption of glucose across the monolayer occurred via a Na+/glucose cotransporter, as indicated by a change in short circuit current after addition of glucose to the apical membrane. When examined under several conditions, neither insulin nor IGF-1 had an affect on the transport of glucose across the Caco-2 monolayer, nor the production of lactate by the cells. It is concluded that the insulin and IGF-1 receptors of Caco-2 cells do not regulate glucose transport.