Tampons as a source of exposure to metal(loid)s.

BACKGROUND: Between 52-86% of people who menstruate in the United States use tampons-cotton and/or rayon/viscose 'plugs'-to absorb menstrual blood in the vagina. Tampons may contain metals from agricultural or manufacturing processes, which could be absorbed by the vagina's highly absorptive tissue, resulting in systemic exposure. To our knowledge, no previous studies have measured metals in tampons. OBJECTIVES: We evaluated the concentrations of 16 metal(loid)s in 30 tampons from 14 tampon brands and 18 product lines and compared the concentrations by tampon characteristics. METHODS: About 0.2 - 0.3 g from each tampon (n = 60 samples) were microwave-acid digested and analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine concentrations of arsenic, barium, calcium, cadmium, cobalt, chromium, copper, iron, manganese, mercury, nickel, lead, selenium, strontium, vanadium, and zinc. We compared concentrations by several tampon characteristics (region of purchase, organic material, brand type) using median quantile mixed models. RESULTS: We found measurable concentrations of all 16 metals assessed. We detected concentrations of several toxic metals, including elevated mean concentrations of lead (geometric mean [GM] = 120 ng/g), cadmium (GM = 6.74 ng/g), and arsenic (GM = 2.56 ng/g). Metal concentrations differed by region of tampon purchase (US versus European Union/United Kingdom), by organic versus non-organic material, and for store- versus name-brand tampons. Most metals differed by organic status; lead concentrations were higher in non-organic tampons while arsenic was higher in organic tampons. No categoriy had consistently lower concentrations of all or most metals. DISCUSSION: Tampon use is a potential source of metal exposure. We detected all 16 metals in at least one sampled tampon, including some toxic metals like lead that has no "safe" exposure level. Future research is needed to replicate our findings and determine whether metals can leach out of tampons and cross the vaginal epithelium into systemic circulation.

A myzozoan-specific protein is an essential membrane-anchoring component of the succinate dehydrogenase complex in Toxoplasma parasites.

Succinate dehydrogenase (SDH) is a protein complex that functions in the tricarboxylic acid cycle and the electron transport chain of mitochondria. In most eukaryotes, SDH is highly conserved and comprises the following four subunits: SdhA and SdhB form the catalytic core of the complex, while SdhC and SdhD anchor the complex in the membrane. Toxoplasma gondii is an apicomplexan parasite that infects one-third of humans worldwide. The genome of T. gondii encodes homologues of the catalytic subunits SdhA and SdhB, although the physiological role of the SDH complex in the parasite and the identity of the membrane-anchoring subunits are poorly understood. Here, we show that the SDH complex contributes to optimal proliferation and O2 consumption in the disease-causing tachyzoite stage of the T. gondii life cycle. We characterize a small membrane-bound subunit of the SDH complex called mitochondrial protein ookinete developmental defect (MPODD), which is conserved among myzozoans, a phylogenetic grouping that incorporates apicomplexan parasites and their closest free-living relatives. We demonstrate that TgMPODD is essential for SDH activity and plays a key role in attaching the TgSdhA and TgSdhB proteins to the membrane anchor of the complex. Our findings highlight a unique and important feature of mitochondrial energy metabolism in apicomplexan parasites and their relatives.

Correction: A screen of drug-like molecules identifies chemically diverse electron transport chain inhibitors in apicomplexan parasites.

[This corrects the article DOI: 10.1371/journal.ppat.1011517.].

An environmental justice analysis of air pollution emissions in the United States from 1970 to 2010.

Over the last decades, air pollution emissions have decreased substantially; however, inequities in air pollution persist. We evaluate county-level racial/ethnic and socioeconomic disparities in emissions changes from six air pollution source sectors (industry [SO2], energy [SO2, NOx], agriculture [NH3], commercial [NOx], residential [particulate organic carbon], and on-road transportation [NOx]) in the contiguous United States during the 40 years following the Clean Air Act (CAA) enactment (1970-2010). We calculate relative emission changes and examine the differential changes given county demographics using hierarchical nested models. The results show racial/ethnic disparities, particularly in the industry and energy generation source sectors. We also find that median family income is a driver of variation in relative emissions changes in all sectors-counties with median family income >$75 K vs. less generally experience larger relative declines in industry, energy, transportation, residential, and commercial-related emissions. Emissions from most air pollution source sectors have, on a national level, decreased following the United States CAA. In this work, we show that the relative reductions in emissions varied across racial/ethnic and socioeconomic groups.

Metagenomes and metagenome-assembled genomes from ex vivo fecal incubations of six unique donors.

We present a donor-specific collection of 78 metagenomes (13/donor) and 143 metagenome-assembled genomes (MAGs), representing the gut microbiomes of six healthy adult human donors. In addition to adding to the catalog of publicly available human gut MAGs, this resource permits a genome-resolved look into microbial co-occurrence across six individuals.

A screen of drug-like molecules identifies chemically diverse electron transport chain inhibitors in apicomplexan parasites.

Apicomplexans are widespread parasites of humans and other animals, and include the causative agents of malaria (Plasmodium species) and toxoplasmosis (Toxoplasma gondii). Existing anti-apicomplexan therapies are beset with issues around drug resistance and toxicity, and new treatment options are needed. The mitochondrial electron transport chain (ETC) is one of the few processes that has been validated as a drug target in apicomplexans. To identify new inhibitors of the apicomplexan ETC, we developed a Seahorse XFe96 flux analyzer approach to screen the 400 compounds contained within the Medicines for Malaria Venture 'Pathogen Box' for ETC inhibition. We identified six chemically diverse, on-target inhibitors of the ETC in T. gondii, at least four of which also target the ETC of Plasmodium falciparum. Two of the identified compounds (MMV024937 and MMV688853) represent novel ETC inhibitor chemotypes. MMV688853 belongs to a compound class, the aminopyrazole carboxamides, that were shown previously to target a kinase with a key role in parasite invasion of host cells. Our data therefore reveal that MMV688853 has dual targets in apicomplexans. We further developed our approach to pinpoint the molecular targets of these inhibitors, demonstrating that all target Complex III of the ETC, with MMV688853 targeting the ubiquinone reduction (Qi) site of the complex. Most of the compounds we identified remain effective inhibitors of parasites that are resistant to Complex III inhibitors that are in clinical use or development, indicating that they could be used in treating drug resistant parasites. In sum, we have developed a versatile, scalable approach to screen for compounds that target the ETC in apicomplexan parasites, and used this to identify and characterize novel inhibitors.

Can traffic-related air pollution trigger myocardial infarction within a few hours of exposure? Identifying hourly hazard periods.

INTRODUCTION: Traffic-related air pollution can trigger myocardial infarction (MI). However, the hourly hazard period of exposure to nitrogen dioxide (NO2), a common traffic tracer, for incident MI has not been fully evaluated. Thus, the current hourly US national air quality standard (100 ppb) is based on limited hourly-level effect estimates, which may not adequately protect cardiovascular health. OBJECTIVES: We characterized the hourly hazard period of NO2 exposure for MI in New York state (NYS), USA, from 2000 to 2015. METHODS: For nine cities in NYS, we obtained data on MI hospitalizations from the NYS Department of Health Statewide Planning and Research Cooperative System and hourly NO2 concentrations from the US Environmental Protection Agency's Air Quality System database. We used city-wide exposures and a case-crossover study design with distributed lag non-linear terms to assess the relationship between hourly NO2 concentrations over 24 h and MI, adjusting for hourly temperature and relative humidity. RESULTS: The mean NO2 concentration was 23.2 ppb (standard deviation: 12.6 ppb). In the six hours preceding MI, we found linearly increased risk with increasing NO2 concentrations. At lag hour 0, a 10 ppb increase in NO2 was associated with 0.2 % increased risk of MI (Rate Ratio [RR]: 1.002; 95 % Confidence Interval [CI]: 1.000, 1.004). We estimated a cumulative RR of 1.015 (95 % CI: 1.008, 1.021) for all 24 lag hours per 10 ppb increase in NO2. Lag hours 2-3 had consistently elevated risk ratios in sensitivity analyses. CONCLUSIONS: We found robust associations between hourly NO2 exposure and MI risk at concentrations far lower than current hourly NO2 national standards. Risk of MI was most elevated in the six hours after exposure, consistent with prior studies and experimental work evaluating physiologic responses after acute traffic exposure. Our findings suggest that current hourly standards may be insufficient to protect cardiovascular health.

Lacticaseibacillus rhamnosus Strain GG (LGG) Regulate Gut Microbial Metabolites, an In Vitro Study Using Three Mature Human Gut Microbial Cultures in a Simulator of Human Intestinal Microbial Ecosystem (SHIME).

In the present research, we investigated changes in the gut metabolome that occurred in response to the administration of the Laticaseibacillus rhamnosus strain GG (LGG). The probiotics were added to the ascending colon region of mature microbial communities established in a human intestinal microbial ecosystem simulator. Shotgun metagenomic sequencing and metabolome analysis suggested that the changes in microbial community composition corresponded with changes to metabolic output, and we can infer linkages between some metabolites and microorganisms. The in vitro method permits a spatially-resolved view of metabolic transformations under human physiological conditions. By this method, we found that tryptophan and tyrosine were mainly produced in the ascending colon region, while their derivatives were detected in the transverse and descending regions, revealing sequential amino acid metabolic pathways along with the colonic tract. The addition of LGG appeared to promote the production of indole propionic acid, which is positively associated with human health. Furthermore, the microbial community responsible for the production of indole propionic acid may be broader than is currently known.

An essential role for an Fe-S cluster protein in the cytochrome c oxidase complex of Toxoplasma parasites.

The mitochondrial electron transport chain (ETC) of apicomplexan parasites differs considerably from the ETC of the animals that these parasites infect, and is the target of numerous anti-parasitic drugs. The cytochrome c oxidase complex (Complex IV) of the apicomplexan Toxoplasma gondii ETC is more than twice the mass and contains subunits not found in human Complex IV, including a 13 kDa protein termed TgApiCox13. TgApiCox13 is homologous to a human iron-sulfur (Fe-S) cluster-containing protein called the mitochondrial inner NEET protein (HsMiNT) which is not a component of Complex IV in humans. Here, we establish that TgApiCox13 is a critical component of Complex IV in T. gondii, required for complex activity and stability. Furthermore, we demonstrate that TgApiCox13, like its human homolog, binds two Fe-S clusters. We show that the Fe-S clusters of TgApiCox13 are critical for ETC function, having an essential role in mediating Complex IV integrity. Our study provides the first functional characterisation of an Fe-S protein in Complex IV.

Sound detection and production mechanisms in aquatic decapod and stomatopod crustaceans.

The sensory systems of crustaceans (aquatic decapods and stomatopods) have adapted to a diverse range of aquatic ecosystems. Sound production in aquatic crustaceans is more widespread than previously thought, and has been shown to play a major role in many of their life-history strategies; however, there are still many gaps in our understanding of their sound reception abilities. Crustaceans have three main sensory receptors for sound - the statocyst, superficial hair cells and chordotonal organs - which are all sensitive to the particle motion component of the sound field, rather than the pressure component. Our current understanding of these receptors is that they are sensitive to low-frequency sounds (<2000 Hz). There are a wide variety of sound-producing mechanisms employed by these animals, ranging from stridulation to implosive cavitation (see Glossary). These signals are used for a range of social behaviours, such as courtship, territorial defence and assessing 'resource guarding'. Furthermore, there are examples of sound signals that exceed their hearing range, highlighting a mismatch in our understanding of their hearing systems. This mismatch provides weight to the suggestion that another sound transmission channel - substrate-borne vibrations - might be at play, particularly because most crustaceans live on or near the seafloor. Finally, suggestions are made regarding potential future work that is needed to fill the substantial gaps in our understanding of how crustaceans hear and produce sound.

Experiences of Farmers Market Vendors in a Healthy Food Incentive Program.

Healthy food incentive programs for Supplemental Nutrition Assistance Program participants, often implemented in farmers markets, have shown promise in improving the purchase and consumption of fruits and vegetables. However, variation in program context, program strategies, and participant populations has produced gaps in knowledge about which healthy food incentive program implementation strategies are most effective, and few studies have focused on farmers market vendors' experiences. This study evaluated experiences of farmers market vendors who participated in the Northwest Arkansas Double Your Dollars (NWA DYD) healthy food incentive program intended to increase access to healthy foods for local Hispanic/Latino and Marshallese community members with low incomes. Data were collected from a convenience sample of vendors participating in NWA DYD at the three largest participating markets on the last Saturday in October 2021. Program staff collected quantitative, categorical, and open-ended data through face-to-face surveys. Forty-one vendors completed the survey. Vendors believed NWA DYD was beneficial and easy to use, expanded their customer base, and increased participation of Hispanic/Latino and Marshallese shoppers. Vendors also identified challenges in participation related to administrative burdens and delayed reimbursements. Vendors did not identify NWA DYD as a driver for expanded production for the upcoming growing season. Vendors' experiences at NWA DYD provide implications for others interested in implementing effective healthy food incentive programs. Improving access to farmers markets through effective healthy food incentive programs is an important step toward increasing consumption of fresh, healthy foods among communities with low incomes facing elevated prevalence of chronic disease.

Effects of electronic cigarettes and hookah (waterpipe) use on home air quality.

INTRODUCTION: A major site of secondhand smoke exposure for children and adults is the home. Few studies have evaluated the impact of e-cigarette or hookah use on home air quality, despite evidence finding toxic chemicals in secondhand e-cigarette aerosols and hookah smoke. We assessed the effect of e-cigarette and hookah use on home air quality and compared it with air quality in homes where cigarettes were smoked and where no smoking or e-cigarette use occurred. METHODS: Non-smoking homes and homes where e-cigarettes, hookah or cigarettes were used were recruited in the New York City area (n=57) from 2015 to 2019. Particulate matter with diameter less than 2.5 µm (PM2.5), black carbon and carbon monoxide (CO) were measured during a smoking or vaping session, both in a 'primary' smoking room and in an adjacent 'secondary' room where no smoking or vaping occurred. Log transformed data were compared with postanalysis of variance Tukey simultaneous tests. RESULTS: Use of hookah significantly increased PM2.5 levels compared with non-smoking homes, in both the primary and secondary rooms, while use of e-cigarettes increased PM2.5 levels only in primary rooms. Additionally, in-home use of hookah resulted in greater CO concentrations than the use of cigarettes in primary rooms. CONCLUSIONS: Use of e-cigarettes or hookah increases air pollution in homes. For hookah, increases in PM2.5 penetrated even into rooms adjacent to where smoking occurs. Extending smoke-free rules inside homes to include e-cigarette and hookah products is needed to protect household members and visitors from passive exposure to harmful aerosols and gases.

Fur, Fin, and Feather: Management of Animal Interactions in Australian Residential Aged Care Facilities.

Animal-assisted interventions (AAI) have been occurring in Australian Residential Aged Care Facilities (RACF) for more than 40 years and may relieve loneliness and improve quality of life. The presence of animals in RACF poses an inherent risk to residents and the animals involved. Little is known about the policies and guidelines for including animals in the Australian RACF. We anticipated that most RACFs would have some policies, but they may lack the detail necessary to keep humans and animals safe. Using an adapted survey, we surveyed and interviewed a small but representative sample of Australian RACF managers. The results demonstrated that RACF did have animal policies; however, the content regarding the need for hand washing, infection prevention, and animal welfare was lacking. Including unregulated family pets in RACF was an unexpected additional risk factor identified during data analysis. There is a need for national guidelines tied to the national aged care policy, which includes training and educational resources for RACF and AAI providers.

The mystery of massive mitochondrial complexes: the apicomplexan respiratory chain.

The mitochondrial respiratory chain is an essential pathway in most studied eukaryotes due to its roles in respiration and other pathways that depend on mitochondrial membrane potential. Apicomplexans are unicellular eukaryotes whose members have an impact on global health. The respiratory chain is a drug target for some members of this group, notably the malaria-causing Plasmodium spp. This has motivated studies of the respiratory chain in apicomplexan parasites, primarily Toxoplasma gondii and Plasmodium spp. for which experimental tools are most advanced. Studies of the respiratory complexes in these organisms revealed numerous novel features, including expansion of complex size. The divergence of apicomplexan mitochondria from commonly studied models highlights the diversity of mitochondrial form and function across eukaryotic life.

The Mediating Effect of E-Cigarette Harm Perception in the Relationship between E-Cigarette Advertising Exposure and E-Cigarette Use.

Exposure to e-cigarette advertising is associated with e-cigarette use among young people. This study examined the mediating effect of e-cigarette harm perception on the above relationship. Cross-sectional survey data were collected from 2112 college students in New York City in 2017-2018. The analytic sample comprised 2078 participants (58.6% females) who provided completed data. Structural equal modeling was performed to examine if e-cigarette harm perception mediated the relationship between e-cigarette advertising exposure (via TV, radio, large signs, print media, and online) and ever e-cigarette use and susceptibility to e-cigarette use. About 17.1% of participants reported ever e-cigarette use. Of never users, 17.5% were susceptible to e-cigarette use. E-cigarette advertising exposure was mainly through online sources (31.5%). Most participants (59.4%) perceived e-cigarettes as equally or more harmful than cigarettes. Advertising exposure showed different effects on e-cigarette harm perception depending on the source of the advertising exposure, but perceiving e-cigarettes as less harmful than cigarettes was consistently associated with e-cigarette use and susceptibility. Low harm perception mediated the association between advertising exposure (via online, TV, and radio) and ever e-cigarette use and between online advertising exposure and e-cigarette use susceptibility. Regulatory actions are needed to address e-cigarette marketing, particularly on the Internet.

Methods for Evaluating Environmental Health Impacts at Different Stages of the Policy Process in Cities.

PURPOSE OF REVIEW: Evaluating the environmental health impacts of urban policies is critical for developing and implementing policies that lead to more healthy and equitable cities. This article aims to (1) identify research questions commonly used when evaluating the health impacts of urban policies at different stages of the policy process, (2) describe commonly used methods, and (3) discuss challenges, opportunities, and future directions. RECENT FINDINGS: In the diagnosis and design stages of the policy process, research questions aim to characterize environmental problems affecting human health and to estimate the potential impacts of new policies. Simulation methods using existing exposure-response information to estimate health impacts predominate at these stages of the policy process. In subsequent stages, e.g., during implementation, research questions aim to understand the actual policy impacts. Simulation methods or observational methods, which rely on experimental data gathered in the study area to assess the effectiveness of the policy, can be applied at these stages. Increasingly, novel techniques fuse both simulation and observational methods to enhance the robustness of impact evaluations assessing implemented policies. The policy process consists of interdependent stages, from inception to end, but most reviewed studies focus on single stages, neglecting the continuity of the policy life cycle. Studies assessing the health impacts of policies using a multi-stage approach are lacking. Most studies investigate intended impacts of policies; focusing also on unintended impacts may provide a more comprehensive evaluation of policies.

An Epidemiologic Review of Menstrual Blood Loss as an Excretion Route for Per- and Polyfluoroalkyl Substances.

PURPOSE OF REVIEW: Menstrual blood loss, a common physiologic occurrence, provides an excretion route for per- and polyfluoroalkyl substances (PFAS) since these chemicals are bound to proteins in blood. To increase awareness of this relationship in environmental epidemiology, we reviewed the available epidemiologic data on menstrual bleeding and PFAS concentrations. RECENT FINDINGS: Initial epidemiologic studies reported generally higher PFAS concentrations in men, menopausal women, and those with a history of hysterectomy compared to premenopausal women. Although subsequent studies investigating menstrual cycle characteristics observed somewhat discrepant results for menstrual irregularity and cycle length, consistent associations have been observed between heavy menstrual bleeding and lower PFAS concentrations. This review highlights the important role of menstrual bleeding on the excretion of PFAS. Given the high prevalence of menstrual bleeding in the population and the implications for environmental epidemiology, we provide recommendations to move this field forward.

Air Pollution in American Indian Versus Non-American Indian Communities, 2000-2018.

Objectives. To compare fine particulate matter (PM2.5) concentrations in American Indian (AI)-populated with those in non-AI-populated counties over time (2000-2018) in the contiguous United States. Methods. We used a multicriteria approach to classify counties as AI- or non--AI-populated. We ran linear mixed effects models to estimate the difference in countywide annual PM2.5 concentrations from well-validated prediction models and monitoring sites (modeled and measured PM2.5, respectively) in AI- versus non-AI-populated counties. Results. On average, adjusted modeled PM2.5 concentrations in AI-populated counties were 0.38 micrograms per cubic meter (95% confidence interval [CI] = 0.23, 0.54) lower than in non-AI-populated counties. However, this difference was not constant over time: in 2000, modeled concentrations in AI-populated counties were 1.46 micrograms per cubic meter (95% CI = 1.25, 1.68) lower, and by 2018, they were 0.66 micrograms per cubic meter (95% CI = 0.45, 0.87) higher. Over the study period, adjusted modeled PM2.5 mean concentrations decreased by 2.13 micrograms per cubic meter in AI-populated counties versus 4.26 micrograms per cubic meter in non-AI-populated counties. Results were similar for measured PM2.5. Conclusions. This study highlights disparities in PM2.5 trends between AI- and non-AI-populated counties over time, underscoring the need to strengthen air pollution regulations and prevention implementation in tribal territories and areas where AI populations live. (Am J Public Health. 2022;112(4): 615-623. https://doi.org/10.2105/AJPH.2021.306650).

Menstrual Products as a Source of Environmental Chemical Exposure: A Review from the Epidemiologic Perspective.

PURPOSE OF REVIEW: Menstrual bleeding is a regular, common occurrence in a substantial portion of the population. Menstruators may use more than 10,000 menstrual products over the lifetime. Given the potential for environmental chemicals in menstrual products to be absorbed by the vulvar and vaginal epithelium into systemic circulation, we reviewed the available data on menstrual products as a source of environmental chemical exposure. RECENT FINDINGS: Nearly two dozen studies have been conducted measuring environmental contaminants in menstrual products; all have detected environmental chemicals but had discrepant conclusions on exposure risks. Only three human studies have investigated menstrual product use and environmental chemical concentrations and all observed associations. Detection of environmental chemicals in menstrual products, in combination with challenges of exposure assessment, scarcity of human studies, and the exceedingly common occurrence of menstrual bleeding, motivates the need for further research. We provide recommendations to move this field forward.