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1.
Nat Commun ; 13(1): 1839, 2022 Apr 05.
Article in English | MEDLINE | ID: covidwho-1778601

ABSTRACT

India as a hotspot for air pollution has heavy black carbon (BC) and dust (DU) loadings. BC has been identified to significantly impact the Indian climate. However, whether BC-climate interactions regulate Indian DU during the premonsoon season is unclear. Here, using long-term Reanalysis data, we show that Indian DU is positively correlated to northern Indian BC while negatively correlated to southern Indian BC. We further identify the mechanism of BC-dust-climate interactions revealed during COVID-19. BC reduction in northern India due to lockdown decreases solar heating in the atmosphere and increases surface albedo of the Tibetan Plateau (TP), inducing a descending atmospheric motion. Colder air from the TP together with warmer southern Indian air heated by biomass burning BC results in easterly wind anomalies, which reduces dust transport from the Middle East and Sahara and local dust emissions. The premonsoon aerosol-climate interactions delay the outbreak of the subsequent Indian summer monsoon.


Subject(s)
Air Pollutants , COVID-19 , Aerosols/analysis , Air Pollutants/analysis , COVID-19/epidemiology , Carbon/analysis , Communicable Disease Control , Dust , Environmental Monitoring/methods , Humans , India/epidemiology , Seasons
2.
Environ Res ; 206: 112624, 2022 04 15.
Article in English | MEDLINE | ID: covidwho-1587833

ABSTRACT

China's unprecedented lockdown to contain the spread of the novel coronavirus disease (COVID-19) in early 2020, provided a tragic natural experiment to investigate the responses of atmospheric pollution to emission reduction at regional scale. Primarily driven by primary emissions, particulate trace elements is vitally important due to their disproportionally adverse impacts on human health and ecosystem. Here 14 trace elements in PM2.5 were selected for continuous measurement hourly in urban representative site of Shanghai, for three different phases: pre-control period (1-23 January 2020), control period (24 January-10 February 2020; overlapped with Chinese Lunar New Year holiday) and post control period (11-26 February 2020) the city's lockdown measures. The results show that all meteorological parameters (including temperature, RH, mixing layer height et al.) were generally consistent among different periods. Throughout the study period, the concentrations of most species displayed a "V-shaped" trend, suggesting significant effects by the restriction measures imposed during the lockdown period. While this is not the case for species like K, Cu and Ba, indicating their unusual origins. As a case study, the geographical origins of Cu were explored. Seven major sources, i.e., Vehicle-related emission (including road dust; indicative of Ca, Fe, Ba, Mn, Zn, Cu; accounting for 30.1%), shipping (Ni; 5.0%), coal combustion (As, Pb; 4.2%), Se and Cr industry (24.9%), nonferrous metal smelting (Au, Hg; 7.5%) and fireworks burning (K, Cu, Ba; 28.3%) were successfully pinpointed based on positive matrix factorization (PMF) analysis. Our source apportionment results also highlight fireworks burning was one of the dominant source of trace elements during the Chinese Lunar New Year holiday. It is worth noting that 56% of the total mass vehicular emissions are affiliated with non-exhaust sources (tire wear, brake wear, and road surface abrasion).


Subject(s)
Air Pollutants , COVID-19 , Trace Elements , Air Pollutants/analysis , China , Communicable Disease Control , Dust/analysis , Ecosystem , Environmental Monitoring , Humans , Particulate Matter/analysis , SARS-CoV-2 , Trace Elements/analysis , Vehicle Emissions/analysis
3.
Indoor Air ; 32(1): e12969, 2022 01.
Article in English | MEDLINE | ID: covidwho-1570729

ABSTRACT

Resuspension of dust from flooring is a major source of human exposure to microbial contaminants, but the persistence of viruses on dust and carpet and the contribution to human exposure are often unknown. The goal of this work is to determine viability of MS2 and Phi6 bacteriophages on cut carpet, looped carpet, and house dust both over time and after cleaning. Bacteriophages were nebulized onto carpet or dust in artificial saliva. Viability was measured at 0, 1, 2, 3, 4, 24, and 48 h and after cleaning by vacuum, steam, hot water extraction, and disinfection. MS2 bacteriophages showed slower viability decay rates in dust (-0.11 hr-1 ), cut carpet (-0.20 hr-1 ), and looped carpet (-0.09 hr-1 ) compared to Phi6 (-3.36 hr-1 , -1.57 hr-1 , and -0.20 hr-1 , respectively). Viable viral concentrations were reduced to below the detection limit for steam and disinfection for both MS2 and Phi6 (p < 0.05), while vacuuming and hot water extraction showed no significant changes in concentration from uncleaned carpet (p > 0.05). These results demonstrate that MS2 and Phi6 bacteriophages can remain viable in carpet and dust for several hours to days, and cleaning with heat and disinfectants may be more effective than standard vacuuming.


Subject(s)
Air Pollution, Indoor , Bacteriophages , Allergens , Dust , Floors and Floorcoverings , Humans
4.
Environ Sci Process Impacts ; 24(1): 17-31, 2022 Jan 26.
Article in English | MEDLINE | ID: covidwho-1541261

ABSTRACT

Microplastics (MPs) are a group of emerging contaminants that have attracted increasing scientific and societal attention over the past decade due to their ubiquitous detection in all environmental compartments. So far, most studies on MPs focus on characterizing their occurrence, fate, and impact in the aquatic environment. Therefore, very little is known about the magnitude, patterns, and associated risks of human exposure to MPs, particularly indoors. This is a significant research gap given that people spend most of their time (up to 90%) indoors, which is exacerbated over the past year by COVID-19 lockdown measures. Critical evaluation of the existing literature revealed the presence of MPs at higher concentrations in indoor air and dust (from homes and offices) compared to outdoors. This was attributed to several factors including: indoor MPs sources (e.g. furniture, textiles), increased deposition of atmospheric MPs indoors, and less atmospheric mixing and dilution compared to outdoor air. Current understanding is that indoor human exposure to MPs occurs via a combination of inhalation, ingestion, and dermal contact. Dietary intake was considered the major pathway of human exposure to MPs until recent studies revealed potential high exposure via inhalation. Moreover, exposure via inadvertent dust ingestion and dermal contact cannot be neglected, particularly for young children. This is alarming due to the potential toxic implications of MPs exposure. Early toxicological evidence indicates that small MPs (<20 µm) can cause oxidative stress and inflammation, while particles <5 µm can be engulfed by cells and translocated to accumulate in different organs. Also, there is increasing concern over potential leaching of toxic chemicals used as plastic additives (e.g. plasticizers and flame retardants) upon exposure to MPs due to their large surface area. However, MPs exposure and risk assessment in humans is still in its infancy and more research is necessary to provide the knowledge base required for regulations to protect human health and environment against MPs.


Subject(s)
Air Pollution, Indoor , COVID-19 , Flame Retardants , Air Pollution, Indoor/analysis , Child, Preschool , Communicable Disease Control , Dust/analysis , Environmental Exposure/analysis , Environmental Monitoring , Flame Retardants/analysis , Humans , Microplastics , Plastics , SARS-CoV-2
6.
Toxins (Basel) ; 13(10)2021 09 28.
Article in English | MEDLINE | ID: covidwho-1481004

ABSTRACT

Despite the awareness that work in the sewage treatment plant is associated with biological hazards, they have not been fully recognised so far. The research aims to comprehensively evaluate microbiological and toxicological hazards in the air and settled dust in workstations in a sewage treatment plant. The number of microorganisms in the air and settled dust was determined using the culture method and the diversity was evaluated using high-throughput sequencing. Endotoxin concentration was assessed with GC-MS (gas chromatography-mass spectrometry) while secondary metabolites with LC-MS/MS (liquid chromatography coupled to tandem mass spectrometry). Moreover, cytotoxicity of settled dust against a human lung epithelial lung cell line was determined with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and UHPLC-Q-ToF-UHRMS (ultra-high-performance liquid chromatography-quadrupole time-of-flight ultrahigh-resolution mass spectrometry) analysis was performed to determine the source of cytotoxicity. The total dust concentration in the sewage treatment plant was low and ranged from 0.030 mg m-3 to 0.044 mg m-3. The highest microbiological contamination was observed in sludge thickening building and screenings storage. Three secondary metabolites were detected in the air and sixteen in the settled dust. They were dominated by compounds typical of lichen and plants and Aspergillus, Penicillium and Fusarium genera mould. The settled dust from the sludge thickening building revealed high cytotoxicity to human lung epithelial cells A-549 (IC50 = 6.98 after 72 h). This effect can be attributed to a biocidal compound-didecyldimethylammonium chloride (DDAC-C10) and seven toxic compounds: 4-hydroxynonenal, carbofuran, cerulenin, diethylphosphate, fenpropimorph, naphthalene and onchidal. The presence of DDAC-C10 and other biocidal substances in the sewage treatment plant environment may bring negative results for biological sewage treatment and the natural environment in the future and contribute to microorganisms' increasing antibiotics resistance. Therefore, the concentration of antibiotics, pesticides and disinfectants in sewage treatment plant workstations should be monitored.


Subject(s)
Aerosols/analysis , Dust/analysis , Occupational Exposure/analysis , Waste Disposal, Fluid , Aerosols/toxicity , Air Microbiology , Cell Line , Disinfectants/analysis , Endotoxins/analysis , Environmental Monitoring , Humans , Sewage/chemistry , Sewage/microbiology , Water Purification
7.
PLoS One ; 16(1): e0244983, 2021.
Article in English | MEDLINE | ID: covidwho-1388896

ABSTRACT

Here we look into the spread of aerosols indoors that may potentially carry viruses. Many viruses, including the novel SARS-CoV-2, are known to spread via airborne and air-dust pathways. From the literature data and our research on the propagation of fine aerosols, we simulate herein the carryover of viral aerosols in indoor air. We demonstrate that a lot of fine droplets released from an infected person's coughing, sneezing, or talking propagate very fast and for large distances indoors, as well as bend around obstacles, lift up and down over staircases, and so on. This study suggests equations to evaluate the concentration of those droplets, depending on time and distance from the source of infection. Estimates are given for the safe distance to the source of infection, and available methods for neutralizing viral aerosols indoors are considered.


Subject(s)
COVID-19/transmission , Disease Transmission, Infectious/prevention & control , Aerosols/analysis , Air Microbiology , Air Pollution, Indoor/analysis , COVID-19/metabolism , COVID-19/virology , Cough , Disease Transmission, Infectious/statistics & numerical data , Dust , Humans , Models, Theoretical , SARS-CoV-2/isolation & purification , Sneezing/physiology , Virus Diseases/prevention & control
8.
Occup Environ Med ; 78(12): 893-899, 2021 12.
Article in English | MEDLINE | ID: covidwho-1388534

ABSTRACT

OBJECTIVE: Unprecedented SARS-CoV-2 infections in farmed minks raised immediate concerns regarding transmission to humans and initiated intensive environmental investigations to assess occupational and environmental exposure. METHODS: Air sampling was performed at infected Dutch mink farms, at farm premises and at nearby residential sites. A range of other environmental samples were collected from minks' housing units, including bedding materials. SARS-CoV-2 RNA was analysed in all samples by quantitative PCR. RESULTS: Inside the farms, considerable levels of SARS-CoV-2 RNA were found in airborne dust, especially in personal inhalable dust samples (approximately 1000-10 000 copies/m3). Most of the settling dust samples tested positive for SARS-CoV-2 RNA (82%, 75 of 92). SARS-CoV-2 RNA was not detected in outdoor air samples, except for those collected near the entrance of the most recently infected farm. Many samples of minks' housing units and surfaces contained SARS-CoV-2 RNA. CONCLUSIONS: Infected mink farms can be highly contaminated with SARS-CoV-2 RNA. This warns of occupational exposure, which was substantiated by considerable SARS-CoV-2 RNA concentrations in personal air samples. Dispersion of SARS-CoV-2 to outdoor air was found to be limited and SARS-CoV-2 RNA was not detected in air samples collected beyond farm premises, implying a negligible risk of environmental exposure to nearby communities. Our occupational and environmental risk assessment is in line with whole genome sequencing analyses showing mink-to-human transmission among farm workers, but no indications of direct zoonotic transmission events to nearby communities.


Subject(s)
Dust/analysis , Environmental Exposure , Farms , Mink/virology , Occupational Exposure , RNA, Viral/isolation & purification , SARS-CoV-2/isolation & purification , Animals , Humans , Netherlands/epidemiology
9.
Sci Rep ; 11(1): 11119, 2021 05 27.
Article in English | MEDLINE | ID: covidwho-1328852

ABSTRACT

To analyse the cause of the atmospheric PM2.5 pollution that occurred during the COVID-19 lockdown in Nanning, Guangxi, China, a single particulate aerosol mass spectrometer, aethalometer, and particulate Lidar coupled with monitoring near-surface gaseous pollutants, meteorological conditions, remote fire spot sensing by satellite and backward trajectory models were utilized during 18-24 February 2020. Three haze stages were identified: the pre-pollution period (PPP), pollution accumulation period (PAP) and pollution dissipation period (PDP). The dominant source of PM2.5 in the PPP was biomass burning (BB) (40.4%), followed by secondary inorganic sources (28.1%) and motor vehicle exhaust (11.7%). The PAP was characterized by a large abundance of secondary inorganic sources, which contributed 56.1% of the total PM2.5 concentration, followed by BB (17.4%). The absorption Ångström exponent (2.2) in the PPP was higher than that in the other two periods. Analysis of fire spots monitored by remote satellite sensing indicated that open BB in regions around Nanning City could be one of the main factors. A planetary boundary layer-relative humidity-secondary particle matter-particulate matter positive feedback mechanism was employed to elucidate the atmospheric processes in this study. This study highlights the importance of understanding the role of BB, secondary inorganic sources and meteorology in air pollution formation and calls for policies for emission control strategies.


Subject(s)
Air Pollutants/analysis , Air Pollution/analysis , Environmental Monitoring/methods , Gases/analysis , Particulate Matter/analysis , Biomass , COVID-19 , China , Dust/analysis , Environmental Monitoring/instrumentation , Environmental Pollution/analysis , Mass Spectrometry/instrumentation , Meteorology , Vehicle Emissions/analysis
10.
Huan Jing Ke Xue ; 42(8): 3644-3651, 2021 Aug 08.
Article in Chinese | MEDLINE | ID: covidwho-1328299

ABSTRACT

To study the evolution and sources of heavy metal elements in the urban atmosphere before, during (overlapped with Chinese Lunar New Year), and after China's COVID-19 shutdown, a multi-metal online analyzer was deployed to determine the trace elements in PM2.5 in Shanghai from January 1 to February 26, 2020. Meanwhile, source apportionment of the hourly measured heavy metal concentrations was performed using a PMF model, in which eight sources were identified. The results show that the concentrations of most elements presented a "V-shaped" trend, which was mainly influenced by emissions from fireworks (K, Cu, Ba as indicative elements), Se-related industry, road dust (Ca, Fe, Ba), and motor vehicles (Mn, Zn, Fe, Cu). However, during the COVID-19 shutdown period, the concentrations of K, Ba, and Cu were high. Case-specific analysis suggested that prior to the shutdown period, the high concentrations of Cu were significantly influenced by long-range transport, which shifted to a dominant contribution from local fireworks during the shutdown period.


Subject(s)
Air Pollutants , COVID-19 , Metals, Heavy , Trace Elements , Air Pollutants/analysis , China , Dust/analysis , Environmental Monitoring , Humans , Particulate Matter/analysis , SARS-CoV-2 , Trace Elements/analysis
11.
Chemosphere ; 286(Pt 1): 131634, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1322021

ABSTRACT

One contemporary issue is how environmental pollution and climate can affect the dissemination and severity of COVID-19 in humans. We documented the first case of association between particulate matter ≤2.5 µm (PM2.5) and COVID-19 mortality rates that involved rural and medium-sized municipalities in northwestern Mexico, where direct air quality monitoring is absent. Alternatively, anthropogenic PM2.5 emissions were used to estimate the PM2.5 exposure in each municipality using two scenarios: 1) considering the fraction derived from combustion of vehicle fuel; and 2) the one derived from modeled anthropogenic sources. This study provides insights to better understand and face future pandemics by examining the relation between PM2.5 pollution and COVID-19 mortality considering the population density and the wind speed. The main findings are: (i) municipalities with high PM2.5 emissions and high population density have a higher COVID-19 mortality rate; (ii) the exceptionally high COVID-19 mortality rates of the rural municipalities could be associated to dust events, which are common in these regions where soils without vegetation are dominant; and (iii) the influence of wind speed on COVID-19 mortality rate was evidenced only in municipalities with <100 inhabitants per km2. These results confirm the suggestion that high levels of air pollutants associated with high population density and an elevated frequency of dust events may promote an extended prevalence and severity of viral particles in the polluted air of urban, suburban, and rural communities. This supports an additional means of dissemination of the coronavirus SARS-CoV-2, in addition to the direct human-to-human transmission.


Subject(s)
Air Pollutants , Air Pollution , COVID-19 , Air Pollutants/analysis , Air Pollution/adverse effects , Air Pollution/analysis , Cities , Dust/analysis , Environmental Monitoring , Humans , Particulate Matter/analysis , Population Density , Rural Population , SARS-CoV-2 , Wind
12.
Sci Rep ; 11(1): 15110, 2021 07 23.
Article in English | MEDLINE | ID: covidwho-1322504

ABSTRACT

The lockdown measures that were taken to combat the COVID-19 pandemic minimized anthropogenic activities and created natural laboratory conditions for studying air quality. Both observations and WRF-Chem simulations show a 20-50% reduction (compared to pre-lockdown and same period of previous year) in the concentrations of most aerosols and trace gases over Northwest India, the Indo Gangetic Plain (IGP), and the Northeast Indian regions. It is shown that this was mainly due to a 70-80% increase in the height of the boundary layer and the low emissions during lockdown. However, a 60-70% increase in the pollutants levels was observed over Central and South India including the Arabian sea and Bay of Bengal during this period, which is attributed to natural processes. Elevated (dust) aerosol layers are transported from the Middle East and Africa via long-range transport, and a decrease in the wind speed (20-40%) caused these aerosols to stagnate, enhancing the aerosol levels over Central and Southern India. A 40-60% increase in relative humidity further amplified aerosol concentrations. The results of this study suggest that besides emissions, natural processes including background meteorology and dynamics, play a crucial role in the pollution concentrations over the Indian sub-continent.


Subject(s)
Air Pollutants/analysis , Air Pollution/analysis , Environmental Monitoring/methods , Vehicle Emissions/analysis , Aerosols/analysis , Africa , Bays , COVID-19 , Communicable Disease Control , Correlation of Data , Dust/analysis , Environmental Pollution/analysis , Humans , India , Meteorology , Middle East , Oceans and Seas , Pandemics
13.
Environ Sci Pollut Res Int ; 28(37): 51948-51960, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1227892

ABSTRACT

Scientific evidence suggests that Saharan dust intrusions in Southern Europe contribute to the worsening of multiple pathologies and increase the concentrations of particulate matter (PM) and other pollutants. However, few studies have examined whether Saharan dust intrusions influence the incidence and severity of COVID-19 cases. To address this question, in this study we carried out generalized linear models with Poisson link between incidence rates and daily hospital admissions and average daily concentrations of PM10, NO2, and O3 in nine Spanish regions for the period from February 1, 2020 to December 31, 2020. The models were adjusted by maximum daily temperature and average daily absolute humidity. Furthermore, we controlled for trend, seasonality, and the autoregressive nature of the series. The variable relating to Saharan dust intrusions was introduced using a dichotomous variable, NAF, averaged across daily lags in ranges of 0-7 days, 8-14 days, 14-21 days, and 22-28 days. The results obtained in this study suggest that chemical air pollutants, and especially NO2, are related to the incidence and severity of COVID-19 in Spain. Furthermore, Saharan dust intrusions have an additional effect beyond what is attributable to the variation in air pollution; they are related, in different lags, to both the incidence and hospital admissions rates for COVID-19. These results serve to support public health measures that minimize population exposure on days with particulate matter advection from the Sahara.


Subject(s)
Air Pollutants , Air Pollution , COVID-19 , Air Pollutants/adverse effects , Air Pollutants/analysis , Air Pollution/adverse effects , Air Pollution/analysis , Dust/analysis , Humans , Incidence , Pandemics , Particulate Matter/analysis , SARS-CoV-2 , Spain/epidemiology
14.
Environ Sci Pollut Res Int ; 28(36): 49989-50000, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1212911

ABSTRACT

The present study evaluated the impact of Saharan dust event on particulate matter (PM: PM10 and PM2.5) concentrations by analyzing the daily average PM data between Saharan dust days (June 23-29, 2020) and non-Saharan dust days (June 15 to June 22 and June 30 to July 12, 2020) for four majorly affected regions in Mexico and by comparing with three major previous events (2015, 2018, and 2019). The results showed that PM10 and PM2.5 concentrations were 2-5 times higher during the Saharan dust event with the highest daily averages of 197 µg/m3 and 94 µg/m3, respectively, and exceeded the Mexican standard norm (NOM-020-SSA1-2014). When comparing with the previous Saharan dust episodes of 2015, 2018, and 2019, the levels of PM10 and PM2.5 considerably increased and more than doubled across Mexico. The correlation analysis revealed a positive association of PM levels with the number of daily COVID-19 cases and deaths during Saharan dust event. Furthermore, the human health risk assessment showed that the chronic daily intake and hazard quotient values incremented during Saharan dust days compared to non-Saharan days, indicating potential health effects and importance of taking necessary measures to ensure better air quality following the COVID-19 pandemic.


Subject(s)
Air Pollutants , Air Pollution , COVID-19 , Air Pollutants/analysis , Air Pollution/analysis , Dust/analysis , Environmental Monitoring , Humans , Mexico , Pandemics , Particulate Matter/analysis , SARS-CoV-2
15.
PLoS One ; 16(4): e0250213, 2021.
Article in English | MEDLINE | ID: covidwho-1197385

ABSTRACT

PURPOSE: To investigate the effectiveness of aerosol clearance using an aerosol box, aerosol bag, wall suction, and a high-efficiency particulate air (HEPA) filter evacuator to prevent aerosol transmission. METHODS: The flow field was visualized using three protective device settings (an aerosol box, and an aerosol bag with and without sealed working channels) and four suction settings (no suction, wall suction, and a HEPA filter evacuator at flow rates of 415 liters per minute [LPM] and 530 LPM). All 12 subgroups were compared with a no intervention group. The primary outcome, aerosol concentration, was measured at the head, trunk, and foot of a mannequin. RESULTS: The mean aerosol concentration was reduced at the head (p < 0.001) but increased at the feet (p = 0.005) with an aerosol box compared with no intervention. Non-sealed aerosol bags increased exposure at the head and trunk (both, p < 0.001). Sealed aerosol bags reduced aerosol concentration at the head, trunk, and foot of the mannequin (p < 0.001). A sealed aerosol bag alone, with wall suction, or with a HEPA filter evacuator reduced the aerosol concentration at the head by 7.15%, 36.61%, and 84.70%, respectively (99.9% confidence interval [CI]: -4.51-18.81, 27.48-45.73, and 78.99-90.40); trunk by 70.95%, 73.99%, and 91.59%, respectively (99.9% CI: 59.83-82.07, 52.64-95.33, and 87.51-95.66); and feet by 69.16%, 75.57%, and 92.30%, respectively (99.9% CI: 63.18-75.15, 69.76-81.37, and 88.18-96.42), compared with an aerosol box alone. CONCLUSIONS: As aerosols spread, an airtight container with sealed working channels is effective when combined with suction devices.


Subject(s)
Aerosols/chemistry , Dust/prevention & control , Suction/methods , Air Filters , Ventilators, Negative-Pressure
16.
Sci Total Environ ; 778: 146201, 2021 Jul 15.
Article in English | MEDLINE | ID: covidwho-1142233

ABSTRACT

Although many COVID-19 patients isolate and recover at home, the dispersal of SARS-CoV-2 onto surfaces and dust within the home environment remains poorly understood. To investigate the distribution and persistence of SARS-CoV-2 in a home with COVID-19 positive occupants, samples were collected from a household with two confirmed COVID-19 cases (one adult and one child). Home surface swab and dust samples were collected two months after symptom onset (and one month after symptom resolution) in the household. The strength of the SARS-CoV-2 molecular signal in fomites varied as a function of sample location, surface material and cleaning practices. Notably, the SARS-CoV-2 RNA signal was detected at several locations throughout the household although cleaning appears to have attenuated the signal on many surfaces. Of the 24 surfaces sampled, 46% were SARS-CoV-2 positive at the time of sampling. The SARS-CoV-2 concentrations in dust recovered from floor and HVAC filter samples ranged from 104 to 105 N2 gene copies/g dust. While detection of viral RNA does not imply infectivity, this study confirms that the SARS-CoV-2 RNA signal can be detected at several locations within a COVID-19 isolation home and can persist after symptoms have resolved. In addition, the concentration of SARS-CoV-2 (normalized per unit mass of dust) recovered in home HVAC filters may prove useful for estimating SARS-CoV-2 airborne levels in homes. In this work, using the quantitative filter forensics methodology, we estimated an average integrated airborne SARS-CoV-2 concentration of 69 ± 43 copies/m3. This approach can be used to help building scientists and engineers develop best practices in homes with COVID-19 positive occupants.


Subject(s)
COVID-19 , RNA, Viral , Adult , Child , Dust , Humans , SARS-CoV-2
17.
Int J Environ Res Public Health ; 18(5)2021 03 08.
Article in English | MEDLINE | ID: covidwho-1134155

ABSTRACT

To control the spread of coronavirus disease (COVID-19), Saudi Arabia's government imposed a strict lockdown during March-July 2020. As a result, the public was confined to indoors, and most of their daily activities were happening in their indoor places, which might have resulted in lower indoor environment quality. Polycyclic aromatic hydrocarbons (PAHs) were analyzed in household dust (n = 40) collected from different residential districts of Jeddah, Saudi Arabia, during the lockdown period. PAHs' levels were two folds higher than the previously reported PAHs in indoor dust from this region. We detected low molecular weight (LMW) with two to four aromatic ring PAHs in all the samples with a significant contribution from Phenanthrene (Phe), present at an average concentration of 1590 ng/g of dust. Although high molecular weight (HMW) (5-6 aromatic ring) PAHs were detected at lower concentrations than LMW PAHs, however, they contributed >90% in the carcinogenic index of PAHs. The estimated daily intake (EDI) of specific PAHs was above the reference dose (RfD) for young children in high-end exposure and the calculated Incremental Lifetime Cancer Risk (ILCR) was >1.00 × 10-4 for both Saudi adults and young children. The study highlighted that indoor pollution has increased significantly during lockdown due to the increased indoor activities and inversely affect human health. This study also warrants to conduct more studies involving different chemicals to understand the indoor environment quality during strict lockdown conditions.


Subject(s)
Air Pollutants , Air Pollution, Indoor , COVID-19 , Coronavirus , Polycyclic Aromatic Hydrocarbons , Adult , Air Pollutants/analysis , Air Pollution, Indoor/analysis , Child , Child, Preschool , Communicable Disease Control , Dust/analysis , Environmental Monitoring , Humans , Pandemics , Polycyclic Aromatic Hydrocarbons/analysis , Risk Assessment , SARS-CoV-2 , Saudi Arabia/epidemiology
18.
Pediatr Allergy Immunol ; 32(5): 963-970, 2021 07.
Article in English | MEDLINE | ID: covidwho-1091019

ABSTRACT

BACKGROUND: Lockdown was imposed for children for 75 days in Turkey to limit the spread of COVID-19. During this period, children have to stay indoors, which might probably increase their exposures to indoor allergens and pollutants. Besides, reduced exposures to respiratory tract infections and outdoor pollutants might be favorable outcomes of this lockdown period. We evaluated the effects of the lockdown on house dust mite (HDM)-sensitized children with respiratory allergies. METHODS: Three-month clinical and medication data of 165 mild-moderate asthmatic children with or without allergic rhinitis (AR), who were grouped according to their HDM sensitization status, were retrieved from patient records. Demographics, asthma control tests, nasal visual analog scores, and outdoor air quality monitoring data were used for assessments in comparisons with the same period in the previous year. RESULTS: Eighty-four patients had asthma, and 81 patients had asthma with AR. Sensitization to HDM was present in 61.8% of the children. Patients experienced reduced numbers of upper respiratory tract infections (P = .008) and reduced asthma exacerbations (P < .001) compared with the same period in the previous year. Asthma control tests were significantly improved (P < .001), and cumulative inhaled corticosteroid usages were significantly reduced (P < .001). Noteworthily, nasal symptoms were significantly worsened in HDM-sensitized asthmatics with AR (P < .001). CONCLUSIONS: This study highlighted that reduction in respiratory tract infections and outdoor pollution may play roles in asthma control and prevent exacerbations despite continuous indoor allergen exposure. Besides, worsening of nasal symptoms in HDM-sensitized asthmatics with AR implies the importance of indoor avoidance measures for AR control.


Subject(s)
Antigens, Dermatophagoides , Asthma , Communicable Disease Control , Allergens , Animals , Asthma/prevention & control , COVID-19/prevention & control , Child , Dust , Humans , Pyroglyphidae/immunology , Turkey
19.
Clin Otolaryngol ; 46(3): 614-618, 2021 May.
Article in English | MEDLINE | ID: covidwho-1061071

ABSTRACT

OBJECTIVES: The aim of this study was to examine contamination from otolaryngologic procedures involving high-speed drilling, specifically mastoid surgery, and to assess the adequacy of PPE in such procedures. DESIGN AND SETTING: Mastoid surgery was simulated in a dry laboratory using a plastic temporal bone, microscope and handheld drill with irrigation and suction. Comparisons of distance of droplet and bone dust contamination and surgeon contamination were made under differing conditions. Irrigation speed, use of microscope and drill burr size and type were compared. MAIN OUTCOME MEASURES: Measurement of the distance of field contamination while performing simulated mastoidectomy and location of surgeon contamination. RESULTS: There was a greater distance field contamination and surgeon contamination without the use of the microscope. Contamination was reduced by using a smaller drill burr and by using a diamond burr when compared to a cutting burr. The use of goggles and a face mask provided good protection for the surgeon. However, the microscope alone may provide sufficient protection to negate the need for goggles. CONCLUSIONS: While the risks of performing mastoid surgery during the coronavirus pandemic cannot be completely removed, they can be mitigated. Such factors include using the microscope for all drilling, using smaller size drill burrs and creating a safe zone around the operating table.


Subject(s)
COVID-19/prevention & control , COVID-19/transmission , Infection Control , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Mastoidectomy , Personal Protective Equipment , Dust , Humans , Models, Anatomic , Suction , Therapeutic Irrigation
20.
World Neurosurg ; 147: e272-e274, 2021 03.
Article in English | MEDLINE | ID: covidwho-1009938

ABSTRACT

OBJECTIVES: Craniotomies/craniostomies have been categorized as aerosol-generating procedures and are presumed to spread coronavirus disease 2019 (COVID-19). However, the presence of severe acute respiratory distress syndrome coronavirus 2 virus in the generated bone dust has never been proved. Our objective is to evaluate the presence of virus in the bone dust (aerosol) generated during emergency neurosurgical procedures performed on patients with active COVID-19. This would determine the true risk of disease transmission during the surgery. METHODS: Ten patients with active COVID-19 infection admitted to our institute in 1 month required emergency craniotomy/craniostomy. The bone dust and mucosal scrapings form paranasal sinuses (if opened) collected during these procedures were tested for the virus using reverse transcription polymerase chain reaction. The entire surgical team was observed for any symptoms related to COVID-19 for 14 days following surgery. RESULTS: Nine patients had moderate viral load in their nasopharyngeal cavity, as detected on reverse transcription polymerase chain reaction. None of the samples of bone dust from these 10 patients tested positive. Mucosal scrapping obtained in 1 patient in which mastoid air cells were inadvertently opened tested negative as well. No health workers from the operating room developed COVID-19-related symptoms. CONCLUSIONS: The bone dust generated during craniotomy/stomy of active patients does not contain the virus. The procedure on an active patient is unlikely to spread the disease. However, a study with larger cohort would be confirmatory.


Subject(s)
Bone and Bones/virology , COVID-19/transmission , Craniotomy , Dust , Nasopharynx/virology , Paranasal Sinuses/virology , Respiratory Mucosa/virology , SARS-CoV-2/genetics , Adolescent , Adult , Aged , Brain Neoplasms/secondary , Brain Neoplasms/surgery , COVID-19 Nucleic Acid Testing , Child , Child, Preschool , Decompressive Craniectomy , Female , Hematoma, Epidural, Cranial/surgery , Hematoma, Subdural, Chronic/surgery , Humans , Hydrocephalus/surgery , Infectious Disease Transmission, Patient-to-Professional , Male , Mastoid , Middle Aged , Ventriculoperitoneal Shunt , Viral Load , Young Adult
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