Light at Night and Risk of Pancreatic Cancer in the NIH-AARP Diet and Health Study.

Circadian disruption may play a role in carcinogenesis. Recent research suggests that light at night (LAN), a circadian disruptor, may be a risk factor for cancer. Moreover, LAN has been linked to obesity and diabetes, two risk factors for pancreatic ductal adenocarcinoma (PDAC). Here we examine the relationship between LAN and PDAC in an epidemiologic study of 464,371 participants from the NIH-AARP Diet and Health Study. LAN was estimated from satellite imagery at baseline (1996), and incident primary PDAC cases were ascertained from state cancer registries. Cox proportional hazards models were used to estimate HRs and two-sided 95% confidence intervals (CI) for the association between quintiles of LAN and PDAC in the overall population stratified by sex. Over up to 16.2 years of follow-up, a total of 2,502 incident PDAC were identified in the cohort. Higher estimated LAN exposure was associated with an elevated PDAC risk. Compared with those living in areas in the lowest LAN quintile, those in areas in the highest quintile had a 27% increase PDAC risk [HR (95% CI), 1.24 (1.03-1.49)], with similar risk for men [1.21 (0.96-1.53)] and women [1.28 (0.94-1.75)]. In addition, stronger associations were observed in normal and overweight groups compared with the obese group (P interaction = 0.03). Our results support the hypothesis that LAN and circadian disruption may be risk factors for PDAC. SIGNIFICANCE: Our study suggests that higher LAN is a risk factor for pancreatic cancer, contributing to the growing literature that demonstrates the potentially adverse health effects of light pollution.

Using night time lights to find regional inequality in India and its relationship with economic development.

Due to unavailability of consistent income data at the sub-state or district level in developing countries, it is difficult to generate consistent and reliable economic inequality estimates at the disaggregated level. To address this issue, this paper employs the association between night time lights and economic activities for India at the sub-state or district-level, and calculates regional income inequality using Gini coefficients. Additionally, we estimate the relationship between night time lights and socio-economic development for regions in India. We employ a newly available data on regional socio-economic development (Social Progress Index), as well as an index that represents institutional quality or governance. Robust to the choice of socio-economic development indicators, our findings indicate that regional inequality measured by night time lights follow the Kuznets curve pattern. This implies that starting from low levels of socio-economic development or quality of institutions, inequality rises as regional socio-economic factors or quality of institutions improve, and with subsequent progress in socio-economic factors or quality of institutions, regional inequality declines.

Effects of a two-phase mixed color lighting program using light-emitting diode lights on layer chickens during brooding and rearing periods.

The behavior, growth and development, and production performance of poultry are affected by the light environment. The influence of light results from a combination of light sources, light intensity, light color, and the photoperiod regimen. With light-emitting diode (LED) lamps applied in poultry housing systems, specific light colors are desired for each time period for layer chickens. The objective of this study was to investigate the effects of a 2-phase mixed color lighting program (phase 1: blue-green, 1 D-13 wk; phase 2: yellow-orange, 14-20 wk) using LED lights on the blood parameters, skeletal development parameters, and sexual development parameters of caged layer chickens during their brooding and rearing periods. Fifty-two chickens were raised from 1 D to 20 wk of age in each of the 4 treatment groups with 3 replicates, with white (400-700 nm) light at phase 1 and phase 2 (WL treatment as the control); blue-green (435-565 nm) light at phase 1 followed by yellow-orange (565-630 nm) light at phase 2 (BG-YOL treatment); yellow-orange LED (565-630 nm) light at phase 1 and phase 2 (YOL treatment); and blue-green (435-565 nm) light at phase 1 and phase 2 (BGL treatment). The results showed that the serum Ig concentrations of the layer chickens in the BG-YOL treatment and BGL treatment were higher than those in the WL treatment at 13 wk of age (P < 0.05). At the age of 20 wk, the serum glucose concentration levels of the pullets after the WL and BGL treatments were lower than those after the YOL treatment (P < 0.05). Compared with the WL treatment, the YOL treatment significantly increased the bone mineral density of the layer chickens (P < 0.05), and BG-YOL treatment promoted the development of the sexual organs (oviducts and ovaries) of the laying hens at the age of 20 wk (P < 0.05). For the 50% egg production age, the YOL treatment was earlier than the other 3 treatments. This study demonstrated that appropriately staged spectral control using LED lights could have positive effects on the immune performance, bone development, and production performance of caged layer chickens during their brooding and rearing periods.

Effects of LED spectra on growth, gas exchange, antioxidant activity and nutritional quality of vegetable species.

This research aimed to investigate the effects of three LED spectra on growth, gas exchange, antioxidant activity and nutritional quality of three vegetable species. The compressible vegetable facilities (CVF) were developed and three kinds of typical LED lights (spectra) were set, including white LED light (W), red-blue-green LED light (RBG), and red-blue-white LED light (RBW). Three vegetable species, i.e. lettuce (Lactuca sativa L. cv. Rome), cherry radish (Raphanus sativas L. cv. Hongxin) and cherry tomato (Lycopersicon esculentum M. cv. Mosite), were chosen and grown (matrix culture) in the three LED lights for 40, 40 and 100 days, respectively. The results indicated that the vegetable plants grew well and were compact in the RBG and RBW treatments. There was the highest biomass or fruit (tomato) in the RBG treatment and the least one in the W treatment for three vegetable species. There were no significant differences in harvest index, ratio of shoot to root, and water content among three treatments. The production efficiency values of 9.0-9.7, 9.9-13.5 and 11.8-12.5 g DW d-1 m-2 for lettuce, radish and tomato plants in the RBG and the RBW treatments were higher than those in the W treatment. The photosynthetic and transpiration rates of three vegetable species in the RBG treatment were the highest among three treatments and the W treatment had the least one. There were significant effects of three spectra on antioxidant activities of three vegetable species. Higher PPFD percentages of blue in the RBG light and the RBW light increased the antioxidant activities of all vegetable plants compared the W light. But it had no significant difference between the RBG light and the RBW. The organic components including soluble sugar (SS) and protein (Prt) of lettuce and radish plants were affected significantly by three spectra, but not for tomato plants. The contents of Mg and Zn of radish plants in the RBG treatment were higher than those in other treatments. There were significant positive effects of RBW treatment on the contents of N and Mg of tomato plants. The different spectra did not affect the contents of N-NO3 and Cu of vegetable plants. This study demonstrated that the RBG light (spectrum) significantly enhanced the growth, gas exchange, antioxidant activity of the lettuce, radish, and tomato cultivars used in this study, and there are significant effects of different LED spectra on the nutritional quality (including organic components and several mineral elements) of the different species.

Visual fatigue during control room work in process industries.

BACKGROUND: Working in front of computer screens is visually demanding and related to adverse eye symptoms. Occurrence of glare further increases visual fatigue. OBJECTIVE: This paper presents results from an examination of visual ergonomics in control room environments at two Swedish process industries. METHODS: Visual conditions were examined and evaluated in nine control rooms and eighteen process operators answered questions about their perceived workload and visual experiences. RESULTS: When working in the control rooms, the mental workload was rated significantly higher by the participants, compared to experienced performance. The operators further experienced significantly higher visual fatigue and blurred vision compared to double vision and sore eyes. Visual demands were increased in conditions where contrast glare was present, as well as frequent changes of focusing distances, and low contrast between background and characters in computer screens. CONCLUSIONS: Suboptimal visual working conditions in the control rooms contributes to increased visual demands on the operators. Presence of glare is leading to visual fatigue and an unnecessary high mental load. The findings support the relevance of considering principles of general and visual ergonomics when designing and organizing work in control rooms. Workstation design should also be flexible to allow for individual and contextual adjustments.

NeoSTRESS: Study of Transfer and Retrieval Environmental StressorS Upon Neonates via a Smartphone Application-Light.

OBJECTIVE: This study aimed to measure the light levels neonates would be exposed to during retrieval, determine whether this varied with transport mode, and compare them with recommended light exposure in neonatal intensive care units. We also aimed to determine the ease of use and acceptability of using the smartphone application. SETTING: A neonatal retrieval service in Brisbane, Australia. METHODS: This prospective study used the calibrated smartphone application Physics Toolbox Sensor Suite (Vieyra Software, Washington, DC). Data were collected during the outbound, nonpatient leg of 45 retrievals (25 road, 11 fixed wing aircraft, and 9 rotary aircraft journeys). Data were saved to Cloud storage and then analyzed using the PostgreSQL database. RESULTS: The median illuminance was 6 lux (interquartile range [IQR], 1-58). The maximum recorded was 93,842 lux. The median illuminance during daytime journeys was 15 lux (IQR, 2-77). The median light level for night journeys was 1 lux (IQR, 0.5-8). Illuminance exceeded the recommended level (600 lux) for 2.1% of all journey time. CONCLUSION: Retrieved neonates can be exposed to light in excess of recommended neonatal intensive care unit levels, including extremely bright light. It is feasible, with good staff acceptability, for a calibrated smartphone application to be used in place of a light meter.

Nighttime safety evaluation for signalized intersections at the signal cycle level based on rear-end conflict models considering lighting and traffic conditions.

Objective: The primary objective of this study is to explore the effects of the lighting level on nighttime safety of signalized intersections based on conflict models under traffic conditions varying in cycles.Method: Nighttime data were collected from a field study at six signalized intersections in Nanjing, Jiangsu Province in China. Nighttime rear-end conflict models were developed by adopting the generalized linear model (GLM) approach to relate the frequency of rear-end traffic conflicts to lighting level, traffic volume and platoon ratio at the signal cycle level.Results: The final model consisting of all explanatory variables, including lighting level, traffic volume, and platoon ratio demonstrates a better performance of safety evaluation when compared to the model considering traffic volume only and the model with traffic volume and an additional variable of lighting or traffic conditions. Nighttime safety of signalized intersections is expected to improve with larger platoon ratios and higher lighting levels. A potential application of the final model was further explored by benefit-cost analyses. The analyses provided a hypothetical recommended lighting level under various traffic volumes and platoon ratios when safety benefit equals lighting system cost.Conclusions: Nighttime safety can be evaluated using the developed rear-end conflict models, which relate the number of rear-end conflicts to traffic and lighting variables. The number of rear-end conflicts can be calculated by the final conflict model with lighting level, traffic volume, and platoon ratio. The developed model can be potentially applied to provide further insights on the lighting management for intersection safety optimization with traffic conditions varying in signal cycles via vehicle-to-infrastructure (V2I) communications.

Effects of Lighting Quality on Working Efficiency of Workers in Office Building in Tanzania.

Background: In this era of Information Communication Technology, a high-quality working environment is essential to the occupants. Providing quantity rather the quality of work environments is very common in most of the least developed countries, including Tanzania. Existing research asserts that poor indoor environmental quality such as lighting has a detrimental effect on human health, and in case of the office working population, it also affects their work performance. This study aims to analyze the effects of the lighting quality on working efficiency of workers in Tanzania. Methods: Four representative offices from the administration building at Mbeya University of Science and Technology were investigated from June to September 2018. The customized questionnaire survey tool was administered to the randomly selected occupants to survey their perceptions about the quality of lighting in their workplace and its influence on their health and work efficiency. Physical observation and illuminance distribution measurements were also conducted. Results: The statistical analysis indicates that the majority of the occupants are less satisfied with the lighting quality in their working environment, and some respondents reported that it significantly affected their work efficiency and wellbeing. The average desk illuminance and uniformity level were found to be below the recommended values of the Chartered Institution of Building Services Engineers (CIBSE) and the International Commission on lighting (CIE). Conclusion: Despite the suggested improvement measures, this research emphasizes that poorly articulated work environment can adversely affect the productivity and work efficiency of the workers. The workers in such condition are also exposed to occupational diseases. Thus, providing a healthy work environment should be a fundamental right of the workers.

Decreased sensitivity of the circadian system to light in current, but not remitted depression.

BACKGROUND: Misalignment of circadian timing in patients with depression has commonly been reported, but the underlying mechanisms are not known. Individual differences in the sensitivity of the circadian system to light affect how the biological clock synchronizes with the external environment and can lead to misalignment of rhythms. We investigated the sensitivity of the circadian system to light in unmedicated (for >3 months) women with a current or previous diagnosis of major depression, and healthy controls. METHODS: Baseline melatonin levels in dim light (<1 lux) were assessed, followed by melatonin levels in normal indoor lighting of 100 lux in order to determine melatonin suppression. RESULTS: Patients currently experiencing a depressive episode showed significantly lower levels of melatonin suppression to light compared to remitted patients and controls, with large effect sizes. Remitted patients and controls showed similar suppression. LIMITATIONS: The relatively small sample, and lack of long-term, within subject assessments, make it difficult to determine the potential causal role of reduced light sensitivity in the development of circadian disruption. CONCLUSIONS: We conclude that hyposensitivity of the circadian system to light may contribute to circadian misalignment in patients with depression. Interventions that increase sensitivity to light or provide stronger light cues may assist in normalizing circadian clock function.

Safety effects of street lighting on roadway segments: Development of a crash modification function.

Objective: Nighttime crashes are overrepresented on the U.S. highway system. Roadway lighting, which provides additional visibility by supplementing vehicle headlights, has been identified as an effective countermeasure to improve nighttime safety. However, the existing literature does not provide a thorough understanding of the effects of street lighting photometric characteristics on nighttime crash occurrence on roadway segments. This study aimed to investigate the relationship between lighting photometric measures and nighttime crash risk on roadway segments and develop a crash modification function/factor (CMF). Methods: The research team collected horizontal illuminance data on 440 roadway segments between 2 successive signalized intersections in Florida for 2012-2014 and matched 4 years of nighttime and daylight crash data (2011-2014). Random parameter negative binomial models were estimated for both nighttime and daylight crash frequencies. The expected night-to-day crash odds ratio, as an equivalent of CMF, was derived from the fitted models with the correction of estimation variances. The confidence intervals (CIs) of the developed CMF were estimated using the Cox method. Results: The coefficient of the mean of horizontal illuminance is significantly negative in the nighttime model. The coefficients of the standard deviation of horizontal illuminance are significantly positive and normally distributed in both the nighttime and daylight models. The significance of the standard deviation in the daylight model captures the confounding effects-a high standard deviation correlates with high traffic exposures, poor safety design standards, and low maintenance quality. The CMF based on the expected daylight-to-day odds ratio was developed as an exponential function of the increments and the increment squares of the mean and the standard deviation of horizontal illuminance. Its 95% CIs indicate that the CMF is almost significant over the whole range. Other significant variables contributing to nighttime crash risk include annual average daily traffic, truck percentage, segment length, access density, undivided roads, and urban/city limits. Conclusions: Horizontal illuminance characteristics have a significant impact on nighttime crash risk on roadway segments. An increase in the mean of horizontal illuminance, indicating an improvement in average lighting level, tends to decrease nighttime crash risk; an increase in the standard deviation, representing a poor uniformity of lighting pattern on a roadway segment, is more likely to raise nighttime crash risk. Because the 2 measures are strongly correlated in a low mean range (<0.44 fc), the 2 photometric measures need to be considered together to interpret the safety effects of lighting patterns. The standard deviation shows better performance in measuring lighting uniformity on a roadway segment than the traditional ratios (max-to-min and mean-to-min). However, a new photometric measure is needed to capture the true lighting pattern influencing driver vision at night.

The effect of light and outdoor activity in natural lighting on the progression of myopia in children.

PURPOSE: To investigate potential risk factors for the progression of myopia. METHODS: Prospective study. Myopic progression was evaluated by cycloplegic autorefraction and axial length (AL) every 6 months in children 6 to 15 years old. Univariate analysis and multiple logistic regression were applied. RESULTS: Around 82 children with median age of 10.3±2.3 years. Myopia progressed by -0.816±0.6 D over 18 months. Increased myopic spherical equivalent refraction (SER) was correlated with increase in AL (P<0.001). Univariate analysis found SER to be significantly associated with: age, especially between 6 and 9.4 years old (P=0.001), parental myopia (P=0.028), and less time spent outdoors (P=0.009). There was a significantly greater increase in SER during months with the least daylight hours (P<0.001). CONCLUSION: Outdoor activities and daylight have a protective effect against increased AL and progression of myopia. Younger children with significant myopia should be monitored closely, especially those around 6 years old with myopic parents.

Providers' Reports of Environmental Conditions and Resources at Births in the United States.

Environmental conditions and resources that may influence provider's behaviors have been investigated in birth environments focusing on location rather than conditions and available resources. Using a descriptive, cross sectional design, we surveyed a random sample of certified nurse-midwives (CNMs), obstetricians, family practice physicians, and certified professional midwives (CPMs) to describe conditions, resources, and workforce present during U.S. births. In all, 1,243 midwives and physicians reported most environmental resources were present at almost 100% of births they attended. Conditions varied: room noise acceptability restriction of phone calls/texts from any source and lighting kept to a minimum. Trainees were present at most births regardless of setting and provider type. The impact of room noise, phone calls/texting, and lighting on outcomes should be determined. The roles and impact of personnel, including trainees, should be described. The extent to which clusters of resources are associated with outcomes might provide new directions for interventions that improve care.

(E-)Cyclists running the red light - The influence of bicycle type and infrastructure characteristics on red light violations.

Red light running is one of the most common traffic violations among cyclists. From different surveys, we know that about 40% of all cyclists run a red light at least occasionally. However, specific data on red light running of e-bike riders (pedelec and S-pedelec riders), a population of cyclists that has been growing steadily in the past few years in Germany and elsewhere, is largely missing. Similarly unclear is the role of the used infrastructure (e.g., carriageway or bike path) or the intersection type on the riders' propensity to run the red light. The goal of this study was to investigate the red light running behaviour of three different bicycle types (bicycle, pedelec, S-pedelec) in Germany, with specific focus on various infrastructure characteristics. We reanalysed data obtained in a naturalistic cycling study, in which we observed 90 participants riding their own bicycles (conventional bicycles, pedelecs, S-pedelecs) on their daily trips over four weeks each. The video material of these trips was annotated and analysed with regard to red light running. Overall, our participants experienced nearly 8000 red light situations. In 16.3% of these situations, they ran the red light, with nearly identical rates for cyclists, pedelec and S-pedelec riders. Red light running rates were lowest when cyclists rode on the carriageway, while the complexity of the intersection appeared to play a role as well. In general, red light running was more common when riders were about to turn right instead of turning left or riding straight through the intersection. Interestingly, we also observed a considerable number of cases in which the riders changed their used infrastructure (e.g., from the carriageway onto the pavement) to avoid a red light.

Feeding and lighting practices on small-scale extensive pastured poultry commercial farms in the United States.

As commercial free-range and pastured poultry production has gained increased popularity in the United States in recent years, there is a greater need to understand basic husbandry practices including feeding and lighting practices. Because husbandry practices vary greatly between individual commercial pastured poultry and free-range operations, gaining knowledge across a wide cross-section of producers is necessary to better understand current practices. Specifically, because feed is considered the most expensive part of poultry production with respect to operating cost, in collaboration with the American Pastured Poultry Producers Association, an on-line survey of commercial free-range and pastured poultry producers was conducted aimed primarily at evaluating feeding and lighting practices. Data were collected from 14 commercial pastured (n = 13) and free-range (n = 1) producers (6 broiler, 1 layer, and 7 broiler/layer facilities) across 9 U.S. states. Results showed that these operations most commonly use Cornish Cross for broiler production and ISA Brown and Australorp for egg production. Only 1 of the 14 farms calculates feed conversion ratio on a monthly basis. Estimates of Hen Month Egg Production (HMEP) resulted in HMEP percentages that were over 100% in 6 of the 7 farms that provided data. 5 of the 7 farms that have layers used supplemental lighting but do not use a lux meter. These lack of data reflect an important challenge with this segment of the poultry industry. Extension based outreach focused on enabling data collection and record-keeping and analysis are necessary. Despite its small sample size, this study's results provide some valuable insights with respect to feeding equipment and the current state of data collection for this segment of the poultry industry.

Bright environmental light improves the sleepiness of nightshift ICU nurses.

BACKGROUND: Shift work can disturb circadian homeostasis and result in fatigue, excessive sleepiness, and reduced quality of life. Light therapy has been shown to impart positive effects in night shift workers. We sought to determine whether or not prolonged exposure to bright light during a night shift reduces sleepiness and enhances psychomotor performance among ICU nurses. METHODS: This is a single-center randomized, crossover clinical trial at a surgical trauma ICU. ICU nurses working a night shift were exposed to a 10-h period of high illuminance (1500-2000 lx) white light compared to standard ambient fluorescent lighting of the hospital. They then completed the Stanford Sleepiness Scale and the Psychomotor Vigilance Test. The primary and secondary endpoints were analyzed using the paired t test. A p value <0.05 was considered significant. RESULTS: A total of 43 matched pairs completed both lighting exposures and were analyzed. When exposed to high illuminance lighting subjects experienced reduced sleepiness scores on the Stanford Sleepiness Scale than when exposed to standard hospital lighting: mean (sem) 2.6 (0.2) vs. 3.0 (0.2), p = 0.03. However, they committed more psychomotor errors: 2.3 (0.2) vs. 1.7 (0.2), p = 0.03. CONCLUSIONS: A bright lighting environment for ICU nurses working the night shift reduces sleepiness but increases the number of psychomotor errors. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03331822 . Retrospectively registered on 6 November 2017.

Night light intensity and women's body weight: Evidence from Nigeria.

The prevalence of overweight and obesity are increasing in many African countries and hence becoming regional public health challenges. We employ satellite-based night light intensity data as a proxy for urbanization to investigate the relationship between urbanization and women's body weight. We use two rounds of the Demographic and Health Survey data from Nigeria. We employ both nonparametric and parametric estimation approaches that exploit both the cross-sectional and longitudinal variations in night light intensities. Our empirical analysis reveals nonlinear relationships between night light intensity and women's body weight measures. Doubling the sample's average level of night light intensity is associated with up to a ten percentage point increase in the probability of overweight. However, despite the generally positive relationship between night light intensity and women's body weight, the strength of the relationship varies across the assorted stages of night light intensity. Early stages of night light intensity are not significantly associated with women's body weight, while higher stages of nightlight intensities are associated with higher rates of overweight and obesity. Given that night lights are strong predictors of urbanization and related economic activities, our results hint at nonlinear relationships between various stages of urbanization and women's body weight.

Estimation of consumption potentiality using VIIRS night-time light data.

As an informative proxy measure for a range of urbanisation and socioeconomic variables, satellite-derived night-time light data have been widely used to investigate the diverse anthropogenic activities and reveal social economy development disparities from the regional to the national scale. The new-generation night-time light data have been proven to potentially improve our understanding in the development and inequality of urban social economy due to its high spatial resolution, strong timeliness and minimal background noise. These night-time light data are derived from the visible infrared imaging radiometer suite (VIIRS) instrument with day/night band located on the Suomi National Polar-orbiting Partnership (NPP) satellite. This study proposed a hybrid model to estimate urban consumption potentiality based on the comprehensive information of human activities obtained from the VIIRS night-time light data. Our method established a flexible geographically weighted regression-based estimation model based on the residential consumption data and DN values of the VIIRS data to predict the possible consumption potentiality of other urban areas in dynamic time. The experiment conducted in Guiyang, a provincial capital in China, affirms that our model is proven to have higher accuracy compared with traditional regression models and can potentially provide guidance for improved business management and increased profit.

Farming habit, light exposure, physical activity, and depressive symptoms. A cross-sectional study of the HEIJO-KYO cohort.

BACKGROUND: Bright light therapy and exercise interventions are effective methods for treating seasonal and non-seasonal affective disorders. Synchronization of internal circadian rhythms with the external environment by light therapy and physical activity may partly explain its efficacy. In the present study, we objectively measured daytime light exposure and physical activity in real life situations with elderly participants, and investigated the association between farming habits and the prevalence of depressive symptoms. METHODS: This cross-sectional was conducted among 1005 participants (mean age: 71.5) of a community-based cohort study. Depressive symptoms were assessed by the Geriatric Depression Scale (GDS score ≥ 6) and administration of antidepressant. RESULTS: Farming habit with long duration (> 7.0 h/week) showed significantly lower odds ratios (OR) for depressive symptoms (adjusted OR 0.63, 95% confidential interval,0.41 to 0.96) compared with participants without farming habit independent of confounders such as age, gender, body mass index smoking, drinking, daytime ambulatory systolic blood pressure, diabetes, living alone, education, income, and daylength. Even in farming with short duration (≤ 7.0 h/week), we found significant association with lower OR for depressive symptoms (adjusted OR 0.64, 95%CI, 0.42 to 0.97). Light exposure and daytime physical activity measured by wrist actigraphy were significantly higher among participants with longer farming habits (p for trend < 0.01). Physical activity mediated 12.0% of association between farming habit and depressive symptoms. LIMITATIONS: A cross-sectional association may be found because the participants with depressive symptoms tended to avoid farming. A longitudinal study is warranted to determine the direction of causality. CONCLUSIONS: Participants with farming habit showed significantly lower OR for depressive symptoms than those without farming habit, and it was partly mediated by physical activity.

Effects of lane departure warning on police-reported crash rates.

OBJECTIVE: To evaluate the effects of lane departure warning (LDW) on single-vehicle, sideswipe, and head-on crashes. METHOD: Police-reported data for the relevant crash types were obtained from 25 U.S. states for the years 2009-2015. Observed counts of crashes with fatalities, injuries, and of all severities for vehicles with LDW were compared with expected counts based on crash involvement rates for the same passenger vehicles without LDW, with exposure by vehicle series, model year, and lighting system standardized between groups. For relevant crashes of all severities and those with injuries, Poisson regression was used to estimate the benefits of LDW while also controlling for demographic variables; fatal crashes were too infrequent to be modeled. RESULTS: Without accounting for driver demographics, vehicles with LDW had significantly lower involvement rates in crashes of all severities (18%), in those with injuries (24%), and in those with fatalities (86%). Adding controls for driver demographics in the Poisson regression reduced the estimated benefit of LDW only modestly in crashes of all severities (11%, p < 0.05) and in crashes with injuries (21%, p < 0.07). CONCLUSIONS: Lane departure warning is preventing the crash types it is designed to address, even after controlling for driver demographics. Results suggest that thousands of lives each year could be saved if every passenger vehicle in the United States were equipped with a lane departure warning system that performed like the study systems. PRACTICAL APPLICATIONS: Purchase of LDW should be encouraged, and, because drivers do not always keep the systems turned on, future efforts should focus on designing systems to encourage greater use and educating consumers about the benefits of using the systems.