Respiratory and nervous system effects of a hydrogen sulfide crisis in Carson, California

Bi-MOF-based point-of-care testing paper for dual-mode detection of H2S

Hydrogen sulfide (H2S) is noxious gas and significantly threatens human health. Herein, a Bi-based metal-organic frameworks (Bi-MOFs) based paper analysis device (PAD) has been developed for rapid and effective dual-mode detection of H2S. The dominant H2S sensing mechanism is explored. The H2S can react with Bi-MOF to form bismuth sulfide (Bi2S3) MOF (Bi2S3-MOF), changing the color of PAD from white to black. The distinguish color change makes it very convenience for visible detection. Meanwhile, the generated Bi2S3-MOF exhibits excellent photothermal property, endowing it possible for photothermal imaging detection. In this regard, the PAD boasts a wide linear detection range of 0-40 μM for H2S with an impressively low limit of detection (LOD) (0.23 μM). The constructed sensing system is demonstrated with outstanding selectivity and storage stability. Satisfied recovery is reached for H2S detection in diverse real samples. Interestingly, the PAD can be used as intelligent label for assessing meat freshness by monitor H2S release from meat under different storage temperatures. With integration capabilities of smartphones, the portable and user-friendly PAD offers a simple and rapid solution for on-the-go detection of H2S in food and environment. The investigation provides an instructive way for environment monitoring and food safety guarding.

Ratiometric fluorescent paper chip for monitoring the freshness of high protein foods

Accurately monitoring the freshness of high-protein foods has significant implications for both food safety and public welfare. Since a large amount of hydrogen sulfide (H2S) is produced during spoilage-related processes, abnormal H2S levels are often considered an important indicator of food spoilage. Therefore, we synthesized novel nanoparticles (NPs) containing Silicon (Si) dots and CdTe quantum dots to accurately assess the amount of sulfide ions (S2-) and thus the quality of high-protein foods in the early stage of storage. As the concentration of S2- increased, the fluorescence intensity of Si/CdTe NPs at λem = 488 nm increased, while the fluorescence intensity at λem = 620 nm was quenched. The fluorescence intensity ratio (F620/F488) was negatively linearly correlated to S2- concentrations in the range of 1-20 μM, with a detection limit of 0.3 μM. Furthermore, to achieve portable detection, we mixed Si/CdTe NPs with sodium carboxymethyl cellulose to prepare effective visual fluorescent sensing paper chips, which exhibited ideal porous structure, good particle dispersion, and excellent fluorescence properties. Incubating the paper chips with high-protein foods allowed for accurate monitoring of food freshness during storage. Therefore, this approach provided a reliable and portable method to determine H2S concentration using a novel concept to ensure the freshness and safety of high-protein foods.

Efficacy of composite bacterial deodorant constructed with Camellia sinensis and its in-situ deodorization mechanism on pig manure

Here, we constructed a novel bacterial deodorant (BD) composed of Delftia tsuruhatensis, Paracoccus denitrificans, Pediococcus acidilactici, and Bacillus velezensis. The BD alone removed 64.84 % of NH3, 100 % of H2S, and 63.68 % of comprehensive odor (OU) during a five-day fermentation of pig manure. The effect was enhanced by introducing Camellia sinensis in the composite bacterial deodorant (CBD) treatment, with the removal efficiency (RE) of NH3 and OU being 88.68 % and 88.14 %, respectively. In prolonged trials, maximum RE of NH3, H2S and OU RE reached 90.16 %, 92.32 % and 100 % in CBD group. Bacterial composition of manure revealed that the abundance of odor-producing microbes (Kurthia, Solibacillus, Proteiniphilum and Acholeplasma) and potential pathogens decreased after CBD application. Functional prediction and correlation analyses indicated that the process of nitrification, denitrification and S/N assimilation were facilitated, while S/N mineralization and methanogenesis processes might be inhibited. This deodorant promoted the conversion of malodorous substances into non-odorous forms, establishing an efficient odor removal system in hoggery. Therefore, the bacterial deodorant compounded with C. sinensis has been shown to be an effective method for deodorizing pig farms. This approach will advance the livestock industry toward greener practices and environmental protection, contributing positively to the development of a sustainable agro-ecosystem.

A network pharmacology and transcriptome analysis of the therapeutic effects of tea tree oil on the lungs of chicks exposed to hydrogen sulfide

This study investigated the use of tea tree oil (TTO) in the treatment of H2S-induced lung injury in chickens, focusing on the detoxification mechanism. H2S can damage the respiratory system and reduce growth performance. TTO can improve immune inflammation and growth performance. The mechanism by which TTO mitigates the harmful effects of H2S on chicken lungs remains unclear. Therefore, the experimental model was established by H2S exposure and TTO addition in drinking water. The 240 one-day-old Roman pink chicks were selected for the experiment. The trial was divided into control group (CON), treatment group (TTG, 0.02 mL/L TTO+H2S) and H2S exposure group (AVG, H2S). There were 4 replicates in each group and the trial lasted for 42 d. The therapeutic effect of TTO on lung injury in chickens were determined by growth performance evaluation, transcription sequencing and network pharmacology analysis. The results showed that in the test's third week, the body weights of the chickens in the CON were higher than those in the AVG and TTG (P < 0.05). Pathological sections showed that TTO alleviated the symptoms of lung inflammation and bleeding caused by ROS. As showed by transcriptional sequencing, the mRNA expression of apoptosis-related genes Caspase-9, BAK-1, BCL-2 and BAX were significantly altered (P < 0.05). Meanwhile, the mRNA expression of inflammation-related genes IL-2, IL-6, and IL-17 were downregulated (P < 0.05). Network pharmacological analysis showed that CA2, CA4, GABRA5 and ADH1C were the key targets of TTO. The TTO treatment significantly altered these targets (P < 0.05). Molecular docking confirmed the strong binding ability between the active component and the targets. This study showed that TTO inhibits H2S-induced oxidative damage to the lungs, thereby improving their health status. This provides a new solution for the prevention of harmful gas in the poultry industry.

High Performance H2S Sensor Based on Ordered Fe2O3/Ti3C2 Nanostructure at Room Temperature

The utilization of a heterogeneous nanojunction design has shown significant enhancements in the gas sensing capabilities of traditional metal oxide gas sensors. In this study, a novel room temperature H2S gas sensor employing Fe2O3 functionalized Ti3C2 MXene as the sensing material has been developed. This sensor exhibits a broad detection range (0.01-500 ppm), low detection limit (10 ppb), and rapid response/recovery times (10 s/15 s), making it ideal for ppb-level H2S detection. The exceptional gas sensitivity of Fe2O3/Ti3C2 composite to H2S can be attributed to several key factors. First, the unique layered frame structure of Fe2O3/Ti3C2 significantly amplifies the surface area of the hybrid material, enhancing the absorption and diffusion capabilities of H2S molecules. Second, the abundance of functional groups (-O, -OH, and -F) on the surface of Ti3C2 MXene nanosheets provides additional active sites for H2S adsorption, The density functional theory calculation confirms that the adsorption energy of the Fe2O3/Ti3C2 composite for H2S (-2.93 eV) is significantly lower than that of pure Fe2O3 (-2.37 eV) and Ti3C2 (-0.2 eV). Lastly, the remarkable metal conductivity of Ti3C2 MXene ensures efficient electron transfer, thereby enhancing overall sensing performance.

Residents' experiences during a hydrogen sulfide crisis in Carson, California

BACKGROUND

In early October 2021, thousands of residents in Carson, California began complaining of malodors and headaches. Hydrogen sulfide (H2S), a noxious odorous gas, was measured at concentrations up to 7000 parts per billion (ppb) and remained above California's acute air quality standard of 30 ppb for a month. Intermittent elevations of H2S continued for 3 months. After 2 months of malodor in this environmental justice community, a government agency attributed the H2S to environmental pollution from a warehouse fire. Research has yielded conflicting results on the health effects of H2S exposure at levels that were experienced during this event. This research fills a critical need for understanding how people perceive and experience emergent environmental health events and will help shape future responses.

METHODS

Through a community-academic partnership, we conducted 6 focus groups with 33 participants who resided in the Carson area during the crisis. We sought to understand how this incident affected residents through facilitated discussion on topics including information acquisition, impressions of the emergency response, health symptoms, and ongoing impacts.

RESULTS

The majority of participants were women (n = 25), identified as Latina/o (n = 19), and rent their homes (n = 21). Participants described difficulty obtaining coherent information about the emergency, which resulted in feelings of abandonment. Most participants felt that local government and healthcare providers downplayed and/or disregarded their concerns despite ongoing odors and health symptoms. Participants described experiencing stress from the odors' unknown health effects and continued fear of future odor incidents. Residents sought to take control of the crisis through information sharing, community networking, and activism. Participants experienced longer term effects from this event, including increased awareness of pollution and reduced trust in local agencies.

DISCUSSION

This study demonstrates the necessity of clear, comprehensive, and prompt responses by relevant decisionmakers to chemical emergencies to appropriately address residents' fears, curb the spread of misinformation, and minimize adverse health effects. Participant responses also point to the benefit of supporting horizontal community networks for improved information sharing. By engaging directly with community members, researchers and disaster responders can better understand the various and complex impacts of chemical disasters and can improve response.