Exposure Levels of Airborne Fungi, Bacteria, and Antibiotic Resistance Genes in Cotton Farms during Cotton Harvesting and Evaluations of N95 Respirators against These Bioaerosols.

The USA is the third-leading cotton-producing country worldwide and cotton farming is common in the state of Georgia. Cotton harvest can be a significant contributor to airborne microbial exposures to farmers and nearby rural communities. The use of respirators or masks is one of the viable options for reducing organic dust and bioaerosol exposures among farmers. Unfortunately, the OSHA Respiratory Protection Standard (29 CFR Part 1910.134) does not apply to agricultural workplaces and the filtration efficiency of N95 respirators was never field-tested against airborne microorganisms and antibiotic resistance genes (ARGs) during cotton harvesting. This study addressed these two information gaps. Airborne culturable microorganisms were sampled using an SAS Super 100 Air Sampler in three cotton farms during cotton harvesting, and colonies were counted and converted to airborne concentrations. Genomic DNA was extracted from air samples using a PowerSoil® DNA Isolation Kit. A series of comparative critical threshold (2-ΔΔCT) real-time PCR was used to quantify targeted bacterial (16S rRNA) genes and major ARGs. Two N95 facepiece respirator models (cup-shaped and pleated) were evaluated for their protection against culturable bacteria and fungi, total microbial load in terms of surface ATP levels, and ARGs using a field experimental setup. Overall, culturable microbial exposure levels ranged between 103 and 104 CFU/m3 during cotton harvesting, which was lower when compared with bioaerosol loads reported earlier during other types of grain harvesting. The findings suggested that cotton harvesting works can release antibiotic resistance genes in farm air and the highest abundance was observed for phenicol. Field experimental data suggested that tested N95 respirators did not provide desirable >95% protections against culturable microorganisms, the total microbial load, and ARGs during cotton harvesting.

Segmentation analysis of the unvaccinated US adult population 2 years into the COVID-19 pandemic, 1 December 2021 to 7 February 2022.

OBJECTIVE: We performed a segmentation analysis of the unvaccinated adult US population to identify sociodemographic and psychographic characteristics of those who were vaccine accepting, vaccine unsure and vaccine averse. DESIGN: Cross-sectional. SETTING: Nationally representative, web-based survey. PARTICIPANTS: 211 303 participants aged ≥18 years were asked in the Household Pulse Survey conducted during 1 December 2021 to 7 February 2022, whether they had ever received a COVID-19 vaccine. Those answering 'No' were asked their receptivity to the vaccine and their responses were categorised as vaccine averse, unsure and accepting. Adjusted prevalence ratios (APR) were calculated in separate multivariable Poisson regression models to evaluate the correlation of the three vaccine dispositions. RESULTS: Overall, 15.2% of US adults were unvaccinated during 1 December 2021 to 7 February 2022, ranging from 5.8% in District of Columbia to 29.0% in Wyoming. Of the entire unvaccinated population nationwide, 51.0% were vaccine averse, 35.0% vaccine unsure and 14.0% vaccine accepting. The likelihood of vaccine aversion was higher among those self-employed (APR=1.11, 95% CI 1.02 to 1.22) or working in a private company (APR=1.09, 95% CI 1.01 to 1.17) than those unemployed; living in a detached, single-family house than in a multiunit apartment (APR=1.15, 95% CI 1.04 to 1.26); and insured by Veterans Affairs/Tricare than uninsured (APR=1.22, 95% CI 1.01 to 1.47). Reasons for having not yet received a vaccine differed among those vaccine accepting, unsure and averse. The percentage reporting logistical or access-related barriers to getting a vaccine (eg, difficulty getting a vaccine, or perceived cost of the vaccine) was relatively higher than those vaccine accepting. Those vaccine unsure reported the highest prevalence of barriers related to perceived safety/effectiveness, including wanting to 'wait and see' if the vaccines were safe (45.2%) and uncertainty whether the vaccines would be effective in protecting them from COVID-19 (29.6%). Those vaccine averse reported the highest prevalence for barriers pertaining to lack of trust in the government or in the vaccines (50.1% and 57.5% respectively), the perception that COVID-19 was not that big of a threat (32.2%) and the perception that they did not need a vaccine (42.3%). CONCLUSIONS: The unvaccinated segment of the population is not a monolith, and a substantial segment may still get vaccinated if constraining factors are adequately addressed.

Geographic, Occupational, and Sociodemographic Variations in Uptake of COVID-19 Booster Doses Among Fully Vaccinated US Adults, December 1, 2021, to January 10, 2022.

Importance: COVID-19 booster vaccine can strengthen waning immunity and widen the range of immunity against new variants. Objective: To describe geographic, occupational, and sociodemographic variations in uptake of COVID-19 booster doses among fully vaccinated US adults. Design, Setting, and Participants: This cross-sectional survey study used data from the Household Pulse Survey conducted from December 1, 2021, to January 10, 2022. Household Pulse Survey is an online, probability-based survey conducted by the US Census Bureau and is designed to yield estimates nationally, by state, and across selected metropolitan areas. Main Outcomes and Measures: Receipt of a booster dose was defined as taking 2 or more doses of COVID-19 vaccines with the first one being the Johnson and Johnson (Janssen) vaccine, or taking 3 or more doses of any of the other COVID-19 vaccines. Weighted prevalence estimates (percentages) were computed overall and among subgroups. Adjusted prevalence ratios (APRs) were calculated in a multivariable Poisson regression model to explore correlates of receiving a booster dose among those fully vaccinated. Results: A total of 135 821 adults completed the survey. Overall, 51.0% were female and 41.5% were aged 18 to 44 years (mean [SD] age, 48.07 [17.18] years). Of fully vaccinated adults, the percentage who reported being boosted was 48.5% (state-specific range, from 39.1% in Mississippi to 66.5% in Vermont). Nationally, the proportion of boosted adults was highest among non-Hispanic Asian individuals (54.1%); those aged 65 years or older (71.4%); those with a doctoral, professional, or master's degree (68.1%); those who were married with no children in the household (61.2%); those with annual household income of $200 000 or higher (69.3%); those enrolled in Medicare (70.9%); and those working in hospitals (60.5%) or in deathcare facilities (eg, funeral homes; 60.5%). Conversely, only one-third of those who ever received a diagnosis of COVID-19, were enrolled in Medicaid, working in pharmacies, with less than a high school education, and aged 18 to 24 years old were boosted. Multivariable analysis of pooled national data revealed that compared with those who did not work outside their home, the likelihood of being boosted was higher among adults working in hospitals (APR, 1.23; 95% CI, 1.17-1.30), ambulatory health care centers (APR, 1.16; 95% CI, 1.09-1.24), and social service settings (APR, 1.08; 95% CI, 1.01-1.15), whereas lower likelihood was seen among those working in food or beverage stores (APR, 0.85; 95% CI, 0.74-0.96) and the agriculture, forestry, fishing, or hunting industries (APR, 0.83; 95% CI, 0.72-0.97). Conclusions and Relevance: These findings suggest continuing disparities in receipt of booster vaccine doses among US adults. Targeted efforts at populations with low uptake may be needed to improve booster vaccine coverage in the US.

Evaluation of a Filtering Facepiece Respirator and a Pleated Particulate Respirator in Filtering Ultrafine Particles and Submicron Particles in Welding and Asphalt Plant Work Environments.

Manufacturing sites, such as welding, casting, and asphalt production (fumes), generate vast numbers of ultrafine particles of <0.1 µm in size and submicron particles close to the ultrafine range (0.1-0.5 µm). Although cumulative masses of these particles are negligible in comparison to the larger particles, the health effects are more severe due to the higher penetration in the human lower respiratory tract, other body parts crossing the respiratory epithelial layers, and the larger surface area. This research investigates the effectiveness of two common commercially available N95 filtering facepieces and N95 pleated particulate respirator models against ultrafine and submicron particles. Two specific types of respirators, the N95 filtering facepiece and the N95 pleated particulate models, in both sealed and unsealed conditions to the manikin face, were tested at various commercial and academic manufacturing sites, a welding and foundry site, and an asphalt production plant. Two TSI Nanoscan SMPS nanoparticle counters were used simultaneously to collect data for particles of 10-420 nm in size from inside and outside of the respirators. While one of them represented the workplace exposure levels, the other one accounted for the exposure upon filtration through the respiratory surfaces. The results showed the particles generated by these manufacturing operations were mostly within the range of from 40 to 200 nm. Results also indicated that while the percentage of filtration levels varied based on the particle size, it remained mostly within the desired protection level of 95% for both of the N95 respirator models in sealed conditions and even for the N95 pleated particulate model in the unsealed condition. However, in the case of the N95 filtering facepiece model, unsealed respirators showed that the percentage of penetration was very high, decreasing the protection levels to 60% in some cases. Although the number of workplace airborne particle levels varied considerably, the filtration percentages were relatively consistent.

Variations of radon and airborne particulate matter near three large phosphogypsum stacks in Florida.

Approximately 1 billion tons of phosphogypsum (PG), a by-product of the fertilizer industry, are currently stacked in Florida. PG emits radon gas, which is a risk factor for lung cancer and can also increase particulate matter (PM) associated non-cancer mortality in exposed individuals. We measured concentrations of atmospheric radon and particulate matter near PG stacks and their short-term variations at different distances to estimate exposures in nearby communities. Specifically, we measured atmospheric levels of radon, and mass concentrations of PM1, PM2.5, and PM10, and number concentrations of PM0.3, PM0.5, PM1, PM2.5, PM5, and PM10 near three large PG stacks in Florida. Atmospheric radon was collected at distances of 2.5, 5.0, and 7.5 miles downwind from three large PG stacks using charcoal-based kits and measured by liquid scintillation counting. A professional radon monitor was used to take 24-h-average radon reading at 5.0 miles from each stack for comparison purposes. The median (IQR) radon levels were 0.325 (0.150, 0.675), 0.150 (0.150, 0.650), and 0.500 (0.150, 0.700) pCi/L at 2.5, 5, and 7.5 miles, respectively. The median (IQR) PM2.5 levels were 5 (4, 6), 5 (3, 7), and 5 (2, 9) µg/m3 at 2.5, 5, and 7.5 miles, respectively. Non-parametric Kruskal-Wallis test could not detect any association between radon or PM levels and distances (2.5-7 miles) from PG stacks. With scintillation counting, median radon levels detected were above the US Environmental Protection Agency (EPA) recommended standard in some of the sites; however, much higher levels were detected through the more advanced digital monitor. PM2.5 levels were below the US-EPA 24-h average national ambient air quality standard in the study area. We conclude that ambient radon levels near PG stacks could exceed US EPA recommended outdoor standards and do not vary within a short distance from the sources, implying similar exposures in nearby communities.