Arsenic (As) exposure is a global public health concern affecting millions worldwide and stems from drinking water and foods containing As. Here, we assessed how agronomic practices and postharvest fermentation techniques influence As concentrations in rice bran, and calculated health risks from consumption. A global suite of 53 rice brans were tested for total As and speciation. Targeted quantification of inorganic As (iAs) concentrations in rice bran were used to calculate Target Hazard Quotient (THQ) and Lifetime Cancer Risk (LCR) across the lifespan. Mean iAs was highest in Thailand rice bran samples (0.619 mg kg⁻¹) and lowest in Guatemala (0.017 mg kg⁻¹) rice bran samples. When comparing monosodium-methanearsonate (MSMA) treated and the Native-soil counterpart under the irrigation technique Alternate Wetting and Drying (AWD) management, the MSMA treatment had significantly higher total As (p = 0.022), and iAs (p = 0.016). No significant differences in As concentrations were found between conventional and organic production, nor between fermented and non-fermented rice bran. Health risk assessment calculations for the highest iAs-rice bran dosage scenario for adults, children and infants exceeded THQ and LCR thresholds, and LCR was above threshold for median iAs-rice bran. This environmental exposure investigation into rice bran provides novel information with food safety guidance for an emerging global ingredient.

The Household Air Pollution Intervention Network trial is a multi-country study on the effects of a liquefied petroleum gas (LPG) stove and fuel distribution intervention on women's and children's health. There is limited data on exposure reductions achieved by switching from solid to clean cooking fuels in rural settings across multiple countries. As formative research in 2017, we recruited pregnant women and characterized the impact of the intervention on personal exposures and kitchen levels of fine particulate matter (PM₂.₅) in Guatemala, India, and Rwanda. Forty pregnant women were enrolled in each site. We measured cooking area concentrations of and personal exposures to PM₂.₅ for 24 or 48 h using gravimetric-based PM₂.₅ samplers at baseline and two follow-ups over two months after delivery of an LPG cookstove and free fuel supply. Mixed models were used to estimate PM₂.₅ reductions. Median kitchen PM₂.₅ concentrations were 296 μg/m³ at baseline (interquartile range, IQR: 158–507), 24 μg/m³ at first follow-up (IQR: 18–37), and 23 μg/m³ at second follow-up (IQR: 14–37). Median personal exposures to PM₂.₅ were 134 μg/m³ at baseline (IQR: 71–224), 35 μg/m³ at first follow-up (IQR: 23–51), and 32 μg/m³ at second follow-up (IQR: 23–47). Overall, the LPG intervention was associated with a 92% (95% confidence interval (CI): 90–94%) reduction in kitchen PM₂.₅ concentrations and a 74% (95% CI: 70–79%) reduction in personal PM₂.₅ exposures. Results were similar for each site. The intervention was associated with substantial reductions in kitchen and personal PM₂.₅ overall and in all sites. Results suggest LPG interventions in these rural settings may lower exposures to the WHO annual interim target-1 of 35 μg/m³. The range of exposure contrasts falls on steep sections of estimated exposure-response curves for birthweight, blood pressure, and acute lower respiratory infections, implying potentially important health benefits when transitioning from solid fuels to LPG.

The Gulf of Honduras includes extensive coral reefs in Belize and Guatemala, classified into four biogeographic zones, which are differentially affected by runoff, hurricanes, and fishing. Runoff mostly impacts the coastal and adjacent channel reefs. The Belize Barrier Reef (BBR) experiences less runoff impact due to the prevailing cyclonic ocean circulation. Hurricane waves powerfully impact the BBR, only occasionally the lee-side of Glover's Reef, and rarely the coastal and channel reefs. Fishing pressure is most intense on the coastal and channel reefs, comparatively modest on the BBR, and low at Glover's Reef. The effects of the three local stressors were evaluated using observations from 24 sites in the Gulf of Honduras. Data were analyzed using the Reef Health Index (RHI), with the highest RHI (4.3) for two Glover's Reef sites, medium RHI (2.6) for 10 sites on the barrier reef, and lowest RHI (2.1) for 8 coastal reef sites.