Bad lighting: Effects of youth indoor tanning prohibitions.

Indoor tanning beds (ITBs) emit UV light at high intensity and have been classified as carcinogenic to humans by the World Health Organization since 2009. We are the first to study the role of state laws prohibiting youths from indoor tanning using a difference-in-differences research design. We find that youth ITB prohibitions reduced population search intensity for tanning-related information. Among white teen girls, ITB prohibitions reduced self-reported indoor tanning and increased sun protective behaviors. We also find that youth ITB prohibitions significantly reduced the size of the indoor tanning market by increasing tanning salon closures and reducing tanning salon sales.

The Effect of Free School Meals on Household Food Purchases: Evidence from the Community Eligibility Provision.

We find access to universal free school meals through the Community Eligibility Provision (CEP) had a meaningful impact on grocery spending for households with children, with monthly food purchases declining by about $11, or 5 percent. For households in zip codes with higher exposure, the decline is as high as $39 per month, or 19 percent. The composition of food purchases also changes after CEP, with low income households experiencing a 3 percent improvement in dietary quality. Finally, CEP exposure is associated with an almost 5 percent decline in households classified as food insecure. Our results on the heterogeneous effects of CEP exposure by prior free/reduced price lunch eligibility reveal benefits in terms of both spending, dietary composition, and food insecurity for previously eligible low-income families, suggesting that the stigma of free school meals may be declining after universal access.

Pollution at schools and children's aerobic capacity.

Poor respiratory health is a major cause of mortality and morbidity worldwide, and children are especially vulnerable. Existing research in economics has documented the effect of pollution on severe health outcomes, such as hospitalizations for asthma and infant death. However, evidence on the effect of air pollution on less extreme measures of respiratory health is limited, because these effects are difficult to measure. Using a more sensitive measure, aerobic capacity ( VO2max ), I study the impact of air pollution on respiratory performance of children. I combine school-grade level data from the California Physical Fitness Test from 2009 to 2017 with local air pollution and weather data to estimate the impact on student aerobic capacity of fluctuations in air pollution levels on testing days. Ozone affects child aerobic capacity at levels even below the Environmental Protection Agency thresholds.

On the road to recovery: Gasoline content regulations and child health.

Gasoline content regulations are designed to curb pollution and improve health, but their impact on health has not been quantified. By exploiting both the timing of regulation and spatial variation in children's exposure to highways, I estimate the effect of gasoline content regulation on pollution and child health. The introduction of cleaner-burning gasoline in California in 1996 reduced asthma admissions by 8% in high exposure areas. Reductions are greatest for areas downwind from highways and heavy traffic areas. Stringent gasoline content regulations can improve child health, and may diminish existing health disparities.

FedExosomes: Engineering Therapeutic Biological Nanoparticles that Truly Deliver.

Many aspects of intercellular communication are mediated through "sending" and "receiving" packets of information via the secretion and subsequent receptor-mediated detection of biomolecular species including cytokines, chemokines, and even metabolites. Recent evidence has now established a new modality of intercellular communication through which biomolecular species are exchanged between cells via extracellular lipid vesicles. A particularly important class of extracellular vesicles is exosomes, which is a term generally applied to biological nanovesicles ~30-200 nm in diameter. Exosomes form through invagination of endosomes to encapsulate cytoplasmic contents, and upon fusion of these multivesicular endosomes to the cell surface, exosomes are released to the extracellular space and transport mRNA, microRNA (miRNA) and proteins between cells. Importantly, exosome-mediated delivery of such cargo molecules results in functional modulation of the recipient cell, and such modulation is sufficiently potent to modulate disease processes in vivo. It is possible that such functional delivery of biomolecules indicates that exosomes utilize native mechanisms (e.g., for internalization and trafficking) that may be harnessed by using exosomes to deliver exogenous RNA for therapeutic applications. A complementary perspective is that understanding the mechanisms of exosome-mediated transport may provide opportunities for "reverse engineering" such mechanisms to improve the performance of synthetic delivery vehicles. In this review, we summarize recent progress in harnessing exosomes for therapeutic RNA delivery, discuss the potential for engineering exosomes to overcome delivery challenges and establish robust technology platforms, and describe both potential challenges and advantages of utilizing exosomes as RNA delivery vehicles.

Health impact assessment of the Atlanta BeltLine.

BACKGROUND: Although a health impact assessment (HIA) is a tool that can provide decision makers with recommendations to promote positive health impacts and mitigate adverse health impacts of proposed projects and policies, it is not routinely conducted on most major projects or policies. PURPOSE: To make health a decision criterion for the Atlanta BeltLine, a multibillion-dollar transit, trails, parks, and redevelopment project. METHODS: An HIA was conducted in 2005-2007 to anticipate and influence the BeltLine's effect on health determinants. RESULTS: Changes in access and equity, environmental quality, safety, social capital, and physical activity were forecast, and steps to maximize health benefits and reduce negative effects were recommended. Key recommendations included giving priority to the construction of trails and greenspace rather than residential and retail construction, making health an explicit goal in project priority setting, adding a public health professional to decision-making boards, increasing the connectivity between the BeltLine and civic spaces, and ensuring that affordable housing is built. BeltLine project decision makers have incorporated most of the HIA recommendations into the planning process. The HIA was cited in the awarding of additional funds of $7,000,000 for brownfield clean-up and greenspace development. The project is expected to promote the health of local residents more than in the absence of the HIA. CONCLUSIONS: This report is one of the first HIAs to tie specific assessment findings to specific recommendations and to identifiable impacts from those recommendations. The lessons learned from this project may help others engaged in similar efforts.

Transgenerational effects of poor elemental food quality on Daphnia magna.

Environmental effects on parents can strongly affect the phenotype of their offspring, which alters the heritability of traits and the offspring's responses to the environment. We examined whether P limitation of the aquatic invertebrate, Daphnia magna, alters the responses of its offspring to inadequate P nutrition. Mother Daphnia consuming P-poor algal food produced smaller neonates having lower body P content compared to control (P-rich) mothers. These offspring from P-stressed mothers, when fed P-rich food, grew faster and reproduced on the same schedule as those from P-sufficient mothers. In contrast, offspring from P-stressed mothers, when fed P-poor food, grew more slowly and had delayed reproduction compared to their sisters born to control mothers. There was also weak evidence that daughters from P-stressed mothers are more susceptible to infection by the virulent bacterium, Pasteuria ramosa. Our results show that P stress is not only transferred across generations, but also that its effect on the offspring generation varies depending upon the quality of their own environment. Maternal P nutrition can thus determine the nature of offspring responses to food P content and potentially obfuscates relationships between the performance of offspring and their own nutrition. Given that food quality can be highly variable within and among natural environments, our results demonstrate that maternal effects should be included as an additional dimension into studies of how elemental nutrition affects the physiology, ecology, and evolution of animal consumers.