Ethnic and gender differences in farm tasks and safety practices among rural California farm youth.

Agricultural work is hazardous and is common among rural youth, especially those living on farms or ranches. Previous work has shown differences in farm work and injury patterns between boys and girls, but little data exist addressing ethnic differences. This study examined ethnic and gender differences in farm tasks, safety attitudes, and use of protective measures among rural California youth working on farms or ranches. The University of California, Davis Youth Agricultural Injury Study is a longitudinal study focusing on agricultural work experience among youth enrolled in an agricultural sciences curriculum in 10 public high schools in California's Central Valley during the 2001-2005 school years. Using cross-sectional data from the initial entrance survey, we studied 946 participants who reported farm work in the previous year. Median annual hours of farm work varied significantly between boys and girls (p < 0.001) and between ethnic groups (p < 0.05) (Hispanic boys: 624 hr; Hispanic girls: 189 hr; White/Other boys: 832 hr; White/Other girls: 468 hr). Girls and Hispanic students were less likely than boys and White/Other students, respectively, to perform hazardous tasks involving tractors, machinery, and chemicals. Median age for initiating work on selected hazardous tasks was up to 3 years later for Hispanic students. Use of task-appropriate safety measures was low in all groups for most hazardous tasks. Boys were more likely than girls to use task-appropriate safety measures, with the exception of seatbelt use when in a car or truck. Hispanic students were more likely than White/Other students to employ safety measures. Girls and Hispanic youth worked fewer farm hours and had reduced exposure to selected hazardous tasks. Use of task-appropriate safety measures was low for all groups but increased for Hispanic students. Further study should explore reasons for low use of safety measures and develop educational efforts to bring about social norm changes promoting their use.

Agricultural injury among rural California public high school students.

OBJECTIVES: The University of California, Davis Youth Agricultural Injury Study characterized the farm work and agricultural injury experience among rural California Central Valley public high school students enrolled in an agricultural sciences curriculum. METHODS: We conducted a cross-sectional survey of agricultural injury among students from 10 California Central Valley high schools during the 2001-2005 school years. RESULTS: Of 1,783 subjects, 946 (53.1%) reported farm work in the previous year, including 97 (10.3%) reporting at least one farm work-related injury in the preceding year. After adjustment for sex, ethnicity, and hours spent in farm work, injury risk was associated with large-animal operations (OR 4.15; 95%CI: 1.18, 14.65), feeding large animals (OR 2.38; 95%CI: 1.15, 4.96), mixing chemicals (OR 1.86; 95%CI: 1.15, 3.03), welding (OR 2.09; 95%CI: 1.17, 3.72), non-use of seatbelts, and frequent riding in the back of an uncovered pick-up truck. Risky attitudes toward farm safety were significantly associated with injury. Girls were more likely to suffer an animal-related injury and boys to suffer injury related to motor vehicles, machinery, or tool use. CONCLUSIONS: Adolescents are at similar risk to adults for agricultural injury. Although limitations on hazardous tasks and time spent on farm work are likely to be the most efficacious means for reducing injury, education will play an important role. Educational measures should include inculcating healthy safety-related attitudes and focus on hazardous tasks, such as those involving animals (for girls) and motor vehicles and machinery (for boys).

Agricultural injury risk among rural California public high school students: prospective results.

OBJECTIVES: To characterize prospective agricultural injury experience among rural California Central Valley public high school students enrolled in agricultural sciences curriculum. METHODS: The University of California, Davis Youth Agricultural Injury Study (UCD-YAIS) examined prospective farm-work injury among students from 10 California Central Valley public high schools. RESULTS: Of eligible subjects, 882 (62.5%) completed at least one annual follow-up survey. Of these, 489 reported farm work in the previous year, including 40 (8.2%) with at least one farm work-related injury. Fractures were the most common injury, especially among girls. Girls were more likely to suffer animal-related injury and boys injury from motor vehicles, machinery, or tool use. Prospective injury risk was strongly associated with prior-year farm injury (OR 8.53; 95% CI 4.02, 18.1) and farm work hours. After adjustment for farm work hours, grade level, and sex, risk was significantly associated with machinery operation, applying chemicals, number of hazardous tasks performed, riding motorcycles or mopeds, riding in back of an uncovered pick-up truck, and smoking. Risky attitude toward farm safety was associated prospectively with injury in stepwise fashion. CONCLUSIONS: Adolescents are at risk for serious farm-work injuries. Although limitations on hazardous tasks and farm work hours are likely to be the most efficacious means for reducing injury, education will play an important role. Education should include inculcating safety-related attitudes and habits and focus on hazardous tasks, such as those involving animals (for girls) and motor vehicles and machinery (for boys), especially among youth with prior farm injury.

Mortality of nontarget arthropods from an aerial application of pyrethrins.

Mortality of nontarget organisms from an ultra-low volume (ULV) aerial application of pyrethrins (Evergreen EC 60-6) was monitored by collecting arthropods from ground tarps placed at the interface of open and canopy areas. A larger number and greater diversity of arthropods were recovered from tarps in the ULV spray area. The observed mortality was approximately 10-fold greater than in the control area. Kruskal-Wallis tests revealed a significant difference in the abundance and diversity of arthropods collected at treatment and control sites at 1 and 12 h postspray. Arthropods, primarily insects, from the treatment area included representatives from 12 orders and > or = 34 families, as compared to 7 orders and 12 families in the control area. Chironomidae (midges) and Formicidae (ants) were the most commonly represented families, accounting for 61% of the arthropods collected from the treatment area; no large-bodied insects (>8 mm) were recovered. Mortality of sentinel mosquitoes in the treatment and control areas averaged 96% and <1%, respectively, at 24 h postexposure. This study supports previous work that the impact of a single ULV application of pyrethrins was limited to a variety of small-bodied arthropods.

Mosquito production in stormwater treatment devices in the Lake Tahoe Basin, California.

In response to increasing evidence of mosquito production in structural stormwater Best Management Practices (BMPs), a collaborative project was developed to document the occurrence, species composition, and seasonal abundance of mosquitoes from selected urban and highway BMPs in the Lake Tahoe Basin, California. Structural and environmental factors associated with mosquito production in highway BMPs were identified and analyzed. Ten species of mosquitoes were collected from 47 BMPs, including Culex tarsalis, Culiseta incidens, Cs. inornata, and 7 species of Aedes. In and around South Lake Tahoe, immatures were most abundant in urban BMPs during the warmer summer and fall months, whereas natural water sources in the surrounding area harbored mosquitoes more often during the colder months of early spring. In BMPs installed along Lake Tahoe's perimeter highways, mosquitoes were observed in 11% of site visits conducted during a single season. Larval presence in highway BMPs was positively associated with water temperature and negatively associated with precipitation, sand, and unspecified organic matter. The significance of mosquito production in BMPs of the Tahoe Basin and the potential for increased transmission of mosquito-borne disease are discussed.

Development time of Culex mosquitoes in stormwater management structures in California.

A widely recommended strategy to minimize mosquito production in structural stormwater Best Management Practices (BMPs) is to ensure they hold captured water for no more than 72 h. However, this standard may be overly conservative for many mosquito species found in urban environments and may impede or prevent the capacity of BMPs to fulfill more stringent water quality standards in environmentally sensitive areas. Egg-to-pupa development of Culex tarsalis, Cx. pipiens, and Cx. quinquefasciatus were examined during July, August, and September 2006 in stormwater management basins and in water collected from these basins in 3 climatically distinct regions of California: the Lake Tahoe Basin, Sacramento Valley, and Los Angeles Basin. The observed minimum times to pupal development were 6 days for Cx. tarsalis and Cx. quinquefasciatus and 8 days for Cx. pipiens. Multiple linear regression models were used to estimate minimum predicted development times under optimal conditions for each region. The results suggest that water residence times of up to 96 h will not significantly increase the potential for Culex mosquito production in stormwater BMPs in the 3 regions included in this study.