In Eswatini, 62.3% of households still rely on solid fuel for cooking, especially wood (61.8%). Smoke emissions during biomass burning remain the primary source of indoor air pollution, comprising pollutants detrimental to health. This study provides a quantitative exposure assessment of fuels used in the Shiselweni region with the objectives of monitoring the carbon monoxide (CO) and carbon dioxide (CO₂) concentrations during cooking events and evaluating cancer and noncancer risks due to exposure to particulate-bound polycyclic aromatic hydrocarbons (PAHs) during cooking events among cooking personnel in households that cook indoors by burning biomass. Real-time CO, CO_2, and particulate matter (PM) monitoring was performed in seventeen kitchens during cooking events across the Shiselweni region using different cooking methods: biomass in open fires and stoves, liquefied petroleum gas (LPG), and electric stoves. PM_2.5, PM_10, and CO exceeded indoor exposure guidelines for biomass fuel-related homesteads. Particulate PAH intake concentrations were evaluated, and biomass fuel users exhibited high cancer risks and low embryo survival chances due to particulate PAH exposure. The average total cost of reducing the incremental lifetime cancer risk (ILCR) and hazard quotient (HQ) to acceptable levels was lower when shifting from biomass to LPG stoves than when shifting to electric stoves. Graphical abstract

Cooking events can generate household air pollutants that deteriorate indoor air quality (IAQ), which poses a threat to human health and well-being. In this study, the emission characteristics and emission factors (EFs) of air pollutants of different meats (beef, lamb, chicken, pork, and fish) cooked by a novel oil-free process and common with-oil processes were investigated. Oil-free cooking tends to emit lower total volatile organic compound (TVOC) levels and fewer submicron smoke particles and can reduce the intake of fat and calories. However, TVOC emissions during oil-free cooking were significantly different, and the lamb EFs were nearly 8 times higher than those during with-oil cooking. The particle-bound polycyclic aromatic hydrocarbon (ƩPPAH) and benzo(a)pyrene-equivalent (ƩBaP_eq) EFs during with-oil cooking ranged from 76.1 to 140.5 ng/g and 7.7–12.4 ng/g, respectively, while those during oil-free cooking ranged from 41.0 to 176.6 ng/g and 5.4–47.6 ng/g, respectively. The ƩPPAH EFs of chicken, pork, and fish were lower during oil-free cooking than during cooking with oil. Furthermore, the ƩBaP_eq EFs of beef, chicken, pork, and fish were lower during oil-free cooking than during cooking with oil. Therefore, it is recommended to use the oil-free method to cook chicken, pork, and fish to reduce ƩPPAH and ƩBaP_eq emissions, but not recommended to cook lamb due to the increase of ƩBaP_eq emissions. The with-oil uncovered cooking EFs of aldehydes ranged from 3.77 to 22.09 μg/g, and those of oil-free cooking ranged from 4.88 to 19.96 μg/g. The aldehyde EFs were lower during oil-free covered cooking than with-oil uncovered cooking for beef, chicken, and fish. This study provides a better realizing of new cooking approaches for the reduction of cooking-induced emission, but further research on the effects of food composition (moisture and fat) and characteristics is needed.

The demand for rice (Oryza sativa L.) as a staple food continues to grow, but rising temperatures due to climate change pose a significant threat to its production. This study addresses the challenge by employing endophytic bacteria and fertilizer to mitigate the adverse effects of high temperatures on rice plants. Seedlings were evaluated for growth parameters, comparing outcomes with non-inoculated counterparts under normal and 40 to 45 °C heat shock conditions. Isolates underwent thorough DNA extraction and 16 S rRNA gene sequencing for identification and were scrutinized for their plant growth-promoting (PGP) traits. The effects of fertilizer and thermotolerant bacteria on rice plants were investigated in controlled chambers at 25 °C for 14 days, succeeded by exposure to 40 °C for 10 days. A consecutive soil pot experiment extended over 150 days, exposing plants to growth chambers set at 35 °C for 60 days, followed by a rapid increase to 40 °C for 30 days and a subsequent reduction to 35 °C for an additional 60 days. Inoculating with the isolates resulted in panicle development and increased plant biomass and length, with fresh grain weights showing a 50% improvement when using bacterial strain W (B. paralicheniformis). Additionally, dry grain weights per panicle rose by 113% with strain W, 83% with strain N (B. pumilus), and 87% with strain D (B. paranthracis) compared to the control. Bacterial strain W exhibited the most pronounced effect on rice yield under heat stress. The results demonstrated a decrease in malondialdehyde (MDA) levels after 150 days of heat stress and half-dose of the recommended fertilizer. Bacterial inoculation increased proline, salicylate, and abscisic acid content, suggesting the alleviation of osmotic stress effects. This highlights the role of endophytic bacteria in stimulating biologically active responses within rice plant cells. Notably, bacterial strains W, N, and D show potential for enhancing plant growth and mitigating heat stress when used in conjunction with NPK50.

High temperatures pose significant challenges to rice plants’ growth and their associated endophytic bacteria. Understanding how these bacteria respond to heat stress is vital. We assessed the potential of five endophytic bacterial strains derived from Oryza sativa—Bacillus tequilensis LB3, B. coagulans LB6, B. paralicheniformis AS9, B. pumilus LB16, and B. paranthracis i40C—to mitigate heat stress effects on rice plants. These strains demonstrated robust abilities in producing indole-3-acetic acid (IAA) and siderophores, nitrogen fixation, and solubilization of phosphate and potassium. Under high-temperature conditions, they significantly enhanced rice plant growth, with increases in plant length of up to 78% at 40 °C. Notably, LB6 showed the highest biomass increase (195%). The strains also improved chlorophyll SPAD values, an indicator of reduced heat stress effects and improved plant health. Phytohormone profiling and biochemical analyses revealed significant increases in abscisic acid (ABA) levels, reduced lipid peroxidation (MDA), and elevated osmoprotectant proline accumulation under heat stress. Inoculated plants exhibited up to 539 ng g⁻¹ of ABA (vs. 62 ng g⁻¹ in uninoculated controls), a 68% reduction in MDA (indicating less oxidative damage), and enhanced proline synthesis, collectively suggesting improved stress adaptation. These changes were linked to bacterial IAA production and nutrient modulation, which alleviated heat-induced physiological decline. These findings underscore the potential of these endophytes as biofertilizers to improve rice resilience under heat stress. Among the strains, LB6 exhibited superior performance, offering the greatest promise for heat-stress mitigation in rice production. This study advances our understanding of phytohormonal, heat stress signaling, and chemical processes underlying bacterial-mediated thermotolerance, providing a foundation for sustainable agricultural strategies. Future research can explore morphological and biochemical analyses, stress-responsive gene expression (e.g., HSPs, DREBs, and APX) linked to thermotolerance, and the combined effects of selected strains with fertilizers in high-temperature rice cultivation.

Improving indoor air quality (IAQ) in hospital environments protects vulnerable patients and healthcare professionals from airborne pollutants and pathogens. This study integrates three interconnected components: a comprehensive analysis of hospital IAQ, an evaluation of a nanosilver/chitosan–titanium dioxide (nano‐Ag/CS‐TiO ₂ ) filter, and an assessment of real‐time monitoring using a cloud‐based platform. The nano‐Ag/CS‐TiO ₂ filter demonstrated enhanced efficiency in reducing a broad spectrum of pollutants, including particulate matter (PM _2.5 and PM ₁₀ ), carbon monoxide, carbon dioxide, volatile organic compounds (VOCs), and microbial aerosols. Measurements were conducted across different hospital zones and timeframes to reflect typical hospital operations and assess the adaptability of the proposed solutions. The study further addresses the long‐term use of nano‐Ag/CS‐TiO ₂ and underscores its advantages over existing filtration methods. Cloud‐based monitoring provides real‐time data, allowing for timely intervention for IAQ, particularly in high‐risk areas like negative pressure isolation rooms. The finding in a negative pressure isolation room demonstrated significant improvement in IAQ postinstallation of the nano‐Ag/CS‐TiO ₂ filtration system. The integration of nano‐Ag/CS‐TiO ₂ filtration and real‐time monitoring supports compliance with World Health Organization (WHO) IAQ standards. These findings highlight the potential for broader application in various healthcare settings, such as outpatient clinics and emergency departments. The study also ensures accuracy in pollutant detection, addressing the potential for false positives and negatives in cloud‐based monitoring. This study highlights that a nano‐Ag/CS‐TiO ₂ filtration system can enhance IAQ in hospital settings by effectively removing air pollutants and inactivating airborne pathogens. This approach facilitates the development of evidence‐based strategies for promoting healthier indoor environments in hospitals.