In hot weather, thermal heat generated by the body, combined with environmental heat from the sun, can lead outdoor workers to experience heat-related stress, severe illness, or even death. The aims of this study were to estimate the prevalence of heat-related symptoms and potential risk factors associated with sun safety–related behavior among Latino farmworkers. Data from interviewer-administered questionnaires were collected from a cross-sectional survey among farmworkers (N = 158) from August to September 2013. Data analysis assessed associations between work activities, sun safety behavior, and the prevalence of heat-related illness (HRI) symptoms among workers. Nearly two thirds (72%) of farmworkers experienced at least one HRI symptom and lacked proper cooling methods when working outdoors. Most workers reported wearing long-sleeved shirts (85%), long pants (98%), and baseball caps (93%). The prevalence of having one HRI symptom was 72% and 27% among workers having three or more HRI symptoms. The majority of farmworkers experience symptoms of HRI and are not provided with proper shade protection when working outdoors. Increased emphasis on administrative controls, particularly educating field supervisors and workers on how to avoid and recognize HRI, should be a priority.
The first aim of this study was to investigate mesoporous activated carbon adsorbents from sisal, hemp, and flax fibers by cost-effective methods. Fibers were impregnated with low concentration (20 wt.%) phosphoric acid. Carbonization temperatures were defined by thermal analysis. Bast fibers (hemp, flax) decompose at lower temperatures (419.36℃, 434.96℃) than leaf fibers (sisal, 512.92℃). The second aim was to compare bast and leaf fibers-derived activated carbon adsorbents by determining physical adsorption properties, chemical compositions, scanning electron microscope, and Fourier transform infrared spectroscopy. Results showed that natural fibers have good candidates to prepare mesoporous activated carbon adsorbents with high surface area (1186–1359 m2/g), high mesopore percentage (60–72%), and high C content (80–86%). Even though leaf-derived activated carbon developed more mesoporous structure (72%), bast-derived activated carbons provided higher surface areas (Shemp = 1359 m2/g; Sflax = 1257 m2/g) and C content. Fourier transform infrared spectra for bast fibers-derived activated carbon adsorbents were quite similar while leaf fiber-derived activated carbon adsorbent had a different spectrum.
1 August 2011 in American Journal of Respiratory Cell and Molecular Biology
Chlorine gas (Cl2) exposure during accidents or in the military setting results primarily in injury to the lungs. However, the potential for Cl2 exposure to promote injury to the systemic vasculature leading to compromised vascular function has not been studied. We hypothesized that Cl2 promotes extrapulmonary endothelial dysfunction characterized by a loss of endothelial nitric oxide synthase (eNOS)-derived signaling. Male Sprague Dawley rats were exposed to Cl2 for 30 minutes, and eNOS-dependent vasodilation of aorta as a function of Cl2 dose (0–400 ppm) and time after exposure (0–48 h) were determined. Exposure to Cl2 (250–400 ppm) significantly inhibited eNOS-dependent vasodilation (stimulated by acetycholine) at 24 to 48 hours after exposure without affecting constriction responses to phenylephrine or vasodilation responses to an NO donor, suggesting decreased NO formation. Consistent with this hypothesis, eNOS protein expression was significantly decreased (∼ 60%) in aorta isolated from Cl2–exposed versus air-exposed rats. Moreover, inducible nitric oxide synthase (iNOS) mRNA was up-regulated in circulating leukocytes and aorta isolated 24 hours after Cl2 exposure, suggesting stimulation of inflammation in the systemic vasculature. Despite decreased eNOS expression and activity, no changes in mean arterial blood pressure were observed. However, injection of 1400W, a selective inhibitor of iNOS, increased mean arterial blood pressure only in Cl2–exposed animals, suggesting that iNOS-derived NO compensates for decreased eNOS-derived NO. These results highlight the potential for Cl2 exposure to promote postexposure systemic endothelial dysfunction via disruption of vascular NO homeostasis mechanisms.
Agricultural work is a physically demanding occupation. The purpose of this project was to describe the prevalence of work-related musculoskeletal disorders (WMSDs) and self-reported pain among Latino farmworkers who work extensively hand harvesting sweet potatoes. Data were obtained from a cross-sectional survey of farmworkers (N = 120) in eastern North Carolina. Univariate and bivariate analyses were used to describe personal, work characteristics, and self-reported pain associated with musculoskeletal injuries. Overall, 79% of farmworkers reported any type of pain or discomfort. The highest reported areas of pain were in the back (66%) and shoulder areas (31%). Younger participants experienced more shoulder pain (P = .04) than older workers, and working more than 5 years as a farmworker was significantly associated with back pain (P = .01). Interventions aimed at administrative and engineering controls for reducing risk factors that contribute to WMSDs are warranted.
Mosquitoes exposed to sublethal doses of insecticides may be selected for resistance to insecticide active ingredients (AIs). Mosquitoes are exposed to AIs through agricultural, public/private mosquito control programs, homeowners, and other sources. Hence, mosquito control programs should routinely measure the resistance/susceptibility status of mosquito populations of public health concern. The objectives here were to determine resistance status for six AIs used in adult mosquito control in the United States to assess how resistance/susceptibility differs between AI, mosquito species (states where > 1 species collected), and between years (some populations sampled for 2 yr). Field-collected eggs from 21 mosquito populations of six different species or hybrid species (Aedes albopictus Skuse [Diptera: Culicidae], Aedes aegypti L. [Diptera: Culicidae], Culex nigripalpus Theobald, Culex pipiens L. [Diptera: Culicidae], Culex quinquefasciatus Say [Diptera: Culicidae], Cx. pipiens/quinquefasciatus) were obtained. Centers for Disease Control and Prevention bottle bioassays were used to assess the resistance/susceptibility status for six AIs (bifenthrin, deltamethrin, etofenprox, malathion, permethrin, and phenothrin). World Health Organization guidelines were used to classify mosquitoes as susceptible (98–100% mortality at diagnostic time [DT]), possibly resistant (80–97% mortality at DT), or resistant (<80% mortality at DT). Significant differences were observed in mosquito susceptibility/resistance between species and AIs. In states where both Aedes and Culex were collected, the odds of exhibiting resistance in Culex were 68–69 times higher than Aedes (Texas odds ratio: 69.30; 95% confidence interval: 5.86, 819.44; P = 0.001; North Carolina odds ratio: 67.99; 95% confidence interval: 15.21, 303.94; P < 0.0001). Some level of resistance was detected against all tested AIs in several mosquito populations and some varied between 2015 and 2016.
The purpose of this study was to assess the attitude toward noise, perceived hearing symptoms, noisy activities that were participated in, and factors associated with hearing protection use among college students. A 44-item online survey was completed by 2,151 college students (aged 17 years and above) to assess the attitudes toward noise, perceived hearing symptoms related to noise exposure, and use of hearing protection around noisy activities. Among the participants, 39.6% experienced at least one hearing symptom, with ear pain as the most frequently reported (22.5%). About 80% of the participants were involved in at least one noise activity, out of which 41% reported the use of hearing protection. A large majority of those with ear pain, hearing loss, permanent tinnitus, and noise sensitivity was involved in attending a sporting event, which was the most reported noisy activity. The highest reported hearing protection use was in the use of firearms, and the lowest in discos/ dances. The reported use of hearing protection is associated with having at least one hearing symptom but the relationship is stronger with tinnitus, hearing loss, and ear pain (χ 2 = 30.5-43.5, P< 0.01) as compared to noise sensitivity (χ 2 = 3.8, P= 0.03); it is also associated with anti-noise attitudes, particularly in youth social events. Universities and colleges have important roles in protecting young adults' hearing by integrating hearing conservation topic in the college curriculum, promoting hearing health by student health services, involving student groups in noise-induced hearing loss (NIHL) awareness and prevention, and establishing noise level limitations for all on-campus events.