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1.
Sci Rep ; 10(1): 21174, 2020 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-33273648

RESUMO

For rebooting economic activities in the ongoing COVID-19 pandemic scenario, it is important to pay detailed attention to infection transfer mechanisms during interaction of people in enclosed environments. Utmost concern is the possibility of aerosol mediated infection transfer, which is largely governed by the size distributions of virus laden droplets, termed as virusols in this work, ejected from humans. We expand on the well-known theory of Poisson fluctuations which acts as statistical barrier against formation of virusols. Analysis suggests that for viral loads < 2 × 105 RNA copies/mL, often corresponding to mild-to-moderate cases of COVID-19, droplets of diameter < 20 µm at the time of emission (equivalent to ~ 10 µm desiccated residue diameter) are unlikely to be of consequence in carrying infections. Cut-off diameters below which droplets will be practically free of contamination, are presented as a function of viral loading. The median diameters of virus laden polydisperse droplet distributions will be 1.5 to 20 times higher depending upon the geometric standard deviation. The studies have implications to risk assessment as well as residence time estimates of airborne infections in indoor environments. Additionally, it will be also helpful for performance evaluation of sanitization and control technologies to mitigate infection risks in workplaces.


Assuntos
Aerossóis/análise , Poluição do Ar em Ambientes Fechados/prevenção & controle , Pandemias/prevenção & controle , Filtros de Ar , Biometria , Expiração , Humanos , Tamanho da Partícula , Medição de Risco , Carga Viral
2.
Environ Health Prev Med ; 25(1): 66, 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33143660

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a new zoonotic agent that emerged in December 2019, causes coronavirus disease 2019 (COVID-19). This infection can be spread by asymptomatic, presymptomatic, and symptomatic carriers. SARS-CoV-2 spreads primarily via respiratory droplets during close person-to-person contact in a closed space, especially a building. This article summarizes the environmental factors involved in SARS-CoV-2 transmission, including a strategy to prevent SARS-CoV-2 transmission in a building environment. SARS-CoV-2 can persist on surfaces of fomites for at least 3 days depending on the conditions. If SARS-CoV-2 is aerosolized intentionally, it is stable for at least several hours. SARS-CoV-2 is inactivated rapidly on surfaces with sunlight. Close-contact aerosol transmission through smaller aerosolized particles is likely to be combined with respiratory droplets and contact transmission in a confined, crowded, and poorly ventilated indoor environment, as suggested by some cluster cases. Although evidence of the effect of aerosol transmission is limited and uncertainty remains, adequate preventive measures to control indoor environmental quality are required, based on a precautionary approach, because COVID-19 has caused serious global damages to public health, community, and the social economy. The expert panel for COVID-19 in Japan has focused on the "3 Cs," namely, "closed spaces with poor ventilation," "crowded spaces with many people," and "close contact." In addition, the Ministry of Health, Labour and Welfare of Japan has been recommending adequate ventilation in all closed spaces in accordance with the existing standards of the Law for Maintenance of Sanitation in Buildings as one of the initial political actions to prevent the spread of COVID-19. However, specific standards for indoor environmental quality control have not been recommended and many scientific uncertainties remain regarding the infection dynamics and mode of SARS-CoV-2 transmission in closed indoor spaces. Further research and evaluation are required regarding the effect and role of indoor environmental quality control, especially ventilation.


Assuntos
Betacoronavirus/fisiologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Ambiente Controlado , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Aerossóis , Poluição do Ar em Ambientes Fechados/prevenção & controle , Aglomeração , Humanos , Ventilação
3.
Toxicol Ind Health ; 36(9): 644-653, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33241766

RESUMO

Coronavirus disease 2019, otherwise referred to as COVID-19, started in China and quickly became a worldwide pandemic. Beginning in March 2020, nonessential businesses in the United States were closed, and many communities were under shelter-in-place orders. As of May 2020, some business sectors started reopening, even amidst concerns of worker health as the pandemic continued. In addition to physical distancing, cleaning and disinfection routines, and using face coverings, building ventilation can also be an important risk mitigation measure for controlling exposure to SARS-CoV-2 indoors. A number of studies to date, however, have focused on ventilation in medical facilities (e.g. hospitals) as the risk of transmission of SARS-CoV-2 is higher there (because of the close proximity of workers to patients who have the disease and their treatment procedures). Few studies have focused on ventilation use in nonmedical settings (e.g. office buildings and school classrooms), despite the large population of workers and community members in these facilities. In this article, we review the role that building ventilation can play in minimizing the risk of SARS-CoV-2 transmission in nonmedical environments and some recommended protocols to follow for its proper use, including cleaning and maintaining mechanical ventilation systems for businesses, schools, and homes.


Assuntos
Poluição do Ar em Ambientes Fechados/prevenção & controle , Ventilação/métodos , Ventilação/normas , /transmissão , Humanos , Pandemias , Local de Trabalho
4.
Toxicol Ind Health ; 36(9): 736-742, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33241768

RESUMO

Risk mitigation of COVID-19 in the indoor environment requires an articulated strategy for creating a bridge between science and the business community that focuses on knitting together four core capabilities-environmental microbiology, transmission science, building science, and social science-advancing scientific knowledge. The purpose of this article is to share insights from the CLEAN 2020 Summit, which assembled leaders from business, policy, standards development, science, and engineering working to mitigate risk of transmission in the built environment. The Summit worked to assess current challenges and pain points felt by industries from around the globe as well as innovative solutions applied to meet these challenges. Although SARS-CoV-2 and the COVID-19 diseases are unique, the foundation of knowledge to assess and mitigate the risk of viral transmission in the built environment is robust. There are opportunities to improve science and engineering technology solutions, processes, and procedures to better meet the dynamic needs of the evolving pandemic.


Assuntos
Ambiente Construído , Gestão de Riscos/métodos , Poluição do Ar em Ambientes Fechados/prevenção & controle , Congressos como Assunto , Saúde Global , Humanos , Pandemias
5.
Artigo em Inglês | MEDLINE | ID: mdl-33036327

RESUMO

Exposure to second-hand smoke (SHS) in the home is largely associated with socio-economic disadvantage. Disadvantaged parents face specific challenges creating a smoke-free home, often caring for children in accommodation without access to outdoor garden space. Existing smoke-free home interventions largely fail to accommodate these constraints. Innovative approaches are required to address this inequality. In this two-phase study, we engaged with parents living in disadvantaged areas of Edinburgh, Scotland, to explore tailored approaches to creating a smoke-free home and develop and pilot-test an intervention based on their views and preferences. In Phase 1, qualitative interviews with 17 parents recruited from Early Years Centres explored alternative approaches to smoke-free home interventions. In Phase 2, an intervention based on parents' views and preferences was pilot-tested with parents recruited through Early Years and Family Nurse Partnership centres. Seventeen parents took part in an interview to share their views/experiences of the intervention. Data from both study phases were thematically analysed. Phase 1 findings suggested that parents associated nicotine replacement therapy (NRT) with quit attempts but supported the idea of NRT use for temporary abstinence to create a smoke-free home, viewing this as a safer option than using e-cigarettes indoors. In Phase 2, 54 parents expressed an interest in accessing NRT to create a smoke-free home, 32 discussed NRT product choice during a home visit from a smoking adviser, and 20 collected their free NRT prescription from the pharmacy. NRT was used for up to 12 weeks in the home, with ongoing advice available from pharmacy staff. During qualitative interviews (n = 17), parents self-reported successfully creating a smoke-free home, quitting smoking, and reduced cigarette consumption, often exceeding their expectations regarding changes made. The intervention was acceptable to parents, but the multi-step process used to access NRT was cumbersome. Some participants were lost to this process. Parents living in disadvantaged circumstances may benefit from access to NRT for temporary abstinence in the home to assist them to protect their children from SHS exposure. Further research using a more streamlined approach to NRT access is required to determine the feasibility and cost-effectiveness of this approach.


Assuntos
Poluição do Ar em Ambientes Fechados/prevenção & controle , Sistemas Eletrônicos de Liberação de Nicotina/estatística & dados numéricos , Exposição Ambiental/prevenção & controle , Pais/psicologia , Abandono do Hábito de Fumar/métodos , Prevenção do Hábito de Fumar/métodos , Poluição por Fumaça de Tabaco/prevenção & controle , Populações Vulneráveis , Adulto , Criança , Pré-Escolar , Feminino , Habitação , Humanos , Lactente , Masculino , Pesquisa Qualitativa , Escócia/epidemiologia , Dispositivos para o Abandono do Uso de Tabaco
7.
Ig Sanita Pubbl ; 76(2): 107-118, 2020.
Artigo em Italiano | MEDLINE | ID: mdl-32877395

RESUMO

Knowledge about the new infectious disease COVID-19, which first spread in the city of Wuhan in China, in December 2019, is based on the evidence retrieved from coronaviruses previously known to humans. The main transmission ways of the new SARS-CoV-2 virus are respiratory droplets and direct and close contact with infected individuals and contaminated surfaces. To date, some scientific publications provide initial evidence that SARS-CoV-2 can be detected in the air, thus assuming a further route of infection, that airborne, although these results are to be considered preliminary and they need careful interpretation. In support of this hypothesis, ventilation systems, aimed to improve indoor air, could represent an easy way to spread and promote the virus infection especially in hospitals and in all health facilities where the presence of infected individuals is potentially high as well as the possibility of infection by air. Indeed, by generating jets of air at different speeds, they can interfere with the mission of respiratory particles and determine an environmental diffusion of the potentially contaminating droplet. Therefore, ventilation systems could provide a potential transmission channel for the viral load able to spread out in indoor air. Nonetheless, good management, technical and operational practices may lead to a low risk of contagion, both in community and health environments.


Assuntos
Poluição do Ar em Ambientes Fechados/prevenção & controle , Infecções por Coronavirus , Pandemias , Pneumonia Viral , Ventilação , Betacoronavirus , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Transmissão de Doença Infecciosa/prevenção & controle , Humanos , Controle de Infecções/métodos , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão
8.
J Occup Environ Hyg ; 17(10): 447-456, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32960737

RESUMO

Bioaerosols are known to be an important transmission pathway for SARS-CoV-2. We report a framework for estimating the risk of transmitting SARS-CoV-2 via aerosols in laboratory and office settings, based on an exponential dose-response model and analysis of air flow and purification in typical heating, ventilation, and air conditioning (HVAC) systems. High-circulation HVAC systems with high-efficiency particulate air (HEPA) filtration dramatically reduce exposure to the virus in indoor settings, and surgical masks or N95 respirators further reduce exposure. As an example of our risk assessment model, we consider the precautions needed for a typical experimental physical science group to maintain a low risk of transmission over six months of operation. We recommend that, for environments where fewer than five individuals significantly overlap, work spaces should remain vacant for between one (high-circulation HVAC with HEPA filtration) to six (low-circulation HVAC with no filtration) air exchange times before a new worker enters in order to maintain no more than 1% chance of infection over six months of operation in the workplace. Our model is readily applied to similar settings that are not explicitly given here. We also provide a framework for evaluating infection mitigation through ventilation in multiple occupancy spaces.


Assuntos
Poluição do Ar em Ambientes Fechados/prevenção & controle , Infecções por Coronavirus/transmissão , Laboratórios/normas , Modelos Estatísticos , Pneumonia Viral/transmissão , Ventilação/normas , Local de Trabalho/normas , Ar Condicionado/normas , Betacoronavirus , Infecções por Coronavirus/epidemiologia , Humanos , Saúde do Trabalhador , Pandemias , Pneumonia Viral/epidemiologia , Medição de Risco
9.
ACS Chem Neurosci ; 11(20): 3177-3179, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-32991148

RESUMO

Several lines of evidence suggest the role of air-conditioning systems in the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Furthermore, the likelihood of novel coronavirus to take refuge inside a microbial Trojan horse, that is, Acanthamoeba, can further enhance possibility of SARS-CoV-2 transmission in the environment. Here we propose the use of various disinfection strategies that can be employed using filters with antimicrobial fabricated surfaces or using UV irradiation to achieve germicidal properties for removal of pathogenic microbes such as SARS-CoV-2 and amoebae in the ventilation systems.


Assuntos
Ar Condicionado/métodos , Filtros de Ar/virologia , Poluição do Ar em Ambientes Fechados/prevenção & controle , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Betacoronavirus/patogenicidade , Desinfecção/métodos , Humanos
10.
J Environ Radioact ; 222: 106351, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32892905

RESUMO

Radon, a gaseous radioactive decay product of naturally-occurring uranium is widely distributed in the environment in rocks and soils and, in certain circumstances, can accumulate in the built environment. Initial studies confirmed a direct link between exposure to both radon gas and its short-lived radioactive progeny, and increased lung-cancer incidence, and demonstrated that radon levels in domestic housing can be sufficiently high to expose occupants to increased risk of lung-cancer. Subsequent studies worldwide have shown that it is cost-effective to detect and reduce domestic radon levels in order to reduce this risk. Recent advances in the early detection of lung-cancer, coupled with the development of improved treatment procedures, have progressively improved survival from the disease, with the numbers surviving at 5 years doubling over recent years, during which period the real costs of lung cancer treatment have risen by around 30%. In the meantime, however, in addition to radon and tobacco-smoke, other airborne pollutants have been identified as risk-factors for lung-cancer. This paper reviews both these actual developments and anticipated future trends, and concludes that since these advances in diagnosis and treatment of lung-cancer have had only a modest effect on cost-effectiveness, it is still important to conduct radon monitoring and remediation programmes. While the general increase in life-expectancy improves the cost-effectiveness of radon remediation programmes significantly, reducing tobacco-smoking incidence reduces that cost-effectiveness but with the overall benefit of reducing radon-related lung-cancers. The challenge remains of encouraging affected householders to remediate their homes to reduce radon levels.


Assuntos
Poluição do Ar em Ambientes Fechados , Neoplasias Pulmonares , Monitoramento de Radiação , Radônio , Poluição do Ar em Ambientes Fechados/economia , Poluição do Ar em Ambientes Fechados/prevenção & controle , Análise Custo-Benefício , Habitação , Humanos , Neoplasias Pulmonares/epidemiologia , Reino Unido
11.
Lancet Public Health ; 5(9): e493-e500, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32888442

RESUMO

BACKGROUND: Many children are exposed to second-hand smoke in the home and are at increased risk of asthma and other respiratory conditions. In Scotland, a public health mass-media campaign was launched on March 24, 2014, called Take it Right Outside (TiRO), with a focus on reducing the exposure of children to domestic second-hand smoke. In this study, our aim was to establish whether the TiRO campaign was followed by a decrease in hospital admissions for childhood asthma and other respiratory conditions related to second-hand smoke exposure across Scotland. METHODS: For an interrupted time-series analysis, data were obtained on all hospital admissions in Scotland between 2000 and 2018 for children aged younger than 16 years. We studied changes in the monthly incidence of admissions for conditions potentially related to second-hand smoke exposure (asthma, lower respiratory tract infection, bronchiolitis, croup, and acute otitis media) per 1000 children following the 2014 TiRO campaign, while considering national legislation banning smoking in public spaces from 2006. We considered asthma to be the primary condition related to second-hand smoke exposure, with monthly asthma admissions as the primary outcome. Gastroenteritis was included as a control condition. The analysis of asthma admissions considered subgroups stratified by age and area quintile of the Scottish Index of Multiple Deprivations (SIMD). FINDINGS: 740 055 hospital admissions were recorded for children. 138 931 (18·8%) admissions were for respiratory conditions potentially related to second-hand smoke exposure, of which 32 342 (23·3%) were for asthma. After TiRO in 2014, we identified a decrease relative to the underlying trend in the slope of admissions for asthma (-0·48% [-0·85 to -0·12], p=0·0096) in younger children (age <5 years), but not in older children (age 5-15 years). Asthma admissions did not change after TiRO among children 0-15 years of age when data were analysed according to area deprivation quintile. Following the 2006 legislation, independent of TiRO, asthma admissions decreased in both younger children (-0·36% [-0·67 to -0·05], p=0·021) and older children (-0·68% [-1·00 to -0·36], p<0·0001), and in children from the most deprived (SIMD 1; -0·49% [-0·87 to -0·11], p=0·011) and intermediate deprived (SIMD 3; -0·70% [-1·17 to -0·23], p=0·0043) area quintiles, but not in those from the least deprived (SIMD 5) area quintile. INTERPRETATION: Our findings suggest that smoke-free home interventions could be an important tool to reduce asthma admissions in young children, and that smoke-free public space legislation might improve child health for many years, especially in the most deprived communities. FUNDING: University of Aberdeen Research Excellence Framework 2021 Impact Support Award Scheme.


Assuntos
Poluição do Ar em Ambientes Fechados/prevenção & controle , Promoção da Saúde , Hospitalização/estatística & dados numéricos , Habitação , Poluição por Fumaça de Tabaco/prevenção & controle , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Análise de Séries Temporais Interrompida , Masculino , Avaliação de Programas e Projetos de Saúde , Escócia
13.
Artigo em Inglês | MEDLINE | ID: mdl-32823587

RESUMO

Household air pollution (HAP) caused by the combustion of solid fuels for cooking and heating is responsible for almost 5% of the global burden of disease. In response, the World Health Organisation (WHO) has recommended the urgent need to scale the adoption of clean fuels, such as liquefied petroleum gas (LPG), in low and middle-income countries (LMICs). To understand the drivers of the adoption and exclusive use of LPG for cooking, we analysed representative survey data from 3343 peri-urban and rural households in Southwest Cameroon. Surveys used standardised tools to collect information on fuel use, socio-demographic and household characteristics and use of LPG for clean cooking. Most households reported LPG to be clean (95%) and efficient (88%), but many also perceived it to be expensive (69%) and unsafe (64%). Positive perceptions about LPG's safety (OR = 2.49, 95% CI = 2.04, 3.05), cooking speed (OR = 4.31, 95% CI = 2.62, 7.10), affordability (OR = 1.7, 95% CI = 1.38, 2.09), availability (OR = 2.17, 95% CI = 1.72, 2.73), and its ability to cook most dishes (OR = 3.79, 95% CI = 2.87, 5.01), were significantly associated with exclusive LPG use. Socio-economic status (higher education) and household wealth (higher income) were also associated with a greater likelihood of LPG adoption. Effective strategies to raise awareness around safe use of LPG and interventions to address financial barriers are needed to scale wider adoption and sustained use of LPG for clean cooking, displacing reliance on polluting solid fuels.


Assuntos
Poluição do Ar em Ambientes Fechados , Culinária , Petróleo , Poluição do Ar em Ambientes Fechados/prevenção & controle , Camarões , Feminino , Humanos , Masculino , População Rural
17.
Yonsei Med J ; 61(4): 310-316, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32233173

RESUMO

PURPOSE: To evaluate the effects of air purifiers on the concentrations of indoor air pollutants and on asthma control in children. MATERIALS AND METHODS: In this randomized crossover trial, daily use of an air purifier filter was compared with a matched placebo with the filter off. Thirty elementary school students who had asthma were enrolled and randomly allocated to one of two groups. The primary endpoints were changes in indoor air quality, asthma severity, lung function, airway inflammatory, urine microbiome, and phthalate after the installation of air purifiers. PM2.5 and CO2 were measured as indoor air pollutants. Asthma severity was assessed in terms of both symptom and medication scores acquired using a daily questionnaire. The higher the score, the better the symptom or the less frequent the use of medication. Peak expiratory flow rate and fractional exhaled nitric oxide were also measured. RESULTS: The mean age of the enrolled patients was 9.2±1.98 years. The mean concentration of PM2.5 was 17.0 µg/m³ in the filter-off condition, but significantly lower at 9.26 µg/m³ in the filter-on condition. Medication scores were 6.9 for the filter-off and 7.12 for the filter-on conditions, reflecting a statistically significant decrease in the frequency of medications used during air purifier operation. Bacterial richness, as determined using the Chao 1 index, was markedly lower in the filter-on than the filter-off condition. CONCLUSION: This study suggests that air purifiers benefit medication burden in children with asthma by reducing PM2.5 levels.


Assuntos
Filtros de Ar/estatística & dados numéricos , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/prevenção & controle , Asma/epidemiologia , Pulmão/fisiologia , Material Particulado/efeitos adversos , Adolescente , Poluição do Ar em Ambientes Fechados/efeitos adversos , Criança , Estudos Cross-Over , Monitoramento Ambiental , Feminino , Humanos , Masculino , Óxido Nítrico , Avaliação de Resultados em Cuidados de Saúde , Material Particulado/análise , Testes de Função Respiratória , Índice de Gravidade de Doença
18.
Lett Appl Microbiol ; 70(6): 396-406, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32180231

RESUMO

Indoor mold grows ubiquitously in humid areas and can affect occupants' health. To prevent indoor mold contamination, one of the key measures suggested by the World Health Organisation and United States Environmental Protection Agency is to maintain an indoor relative humidity (RH) level below 75% or at 30-60%, respectively. However, in tropical and subtropical areas, maintaining these suggested RH levels is equivalent to operating a 24-h air-conditioner (AC) or dehumidifier, which is energy-consuming. As a large part of building expense, the operation time of ACs has been regularly proposed to be cut down because of the requirement of building sustainability. This leads to a trade-off between sustainable building performance and indoor mold hygiene. To balance this trade-off, more sustainable alternatives, such as those that target physical environments (e.g. nutrient and temperature level) or apply new surface coating technologies to inhibit mold growth, have been launched. Despite these initiatives, indoor mold contamination remains an unresolved issue, mainly because these alternative measures only exhibit limited effectiveness or require extra effort. This review aims to summarize the currently adopted mold control measures and discuss their limitations as well as the direction for the future development of sustainable mold control strategies. SIGNIFICANCE AND IMPACT OF THE STUDY: People spend most of their time indoors and hence the presence of indoor mold contamination can compromise the occupants' health. With the wake of climate change which is expected to see an increase in RH and temperature, tropical and subtropical areas are even more prone to mold contamination than they used to be. This study may help facilitate the development of sustainable and effective mold control strategies in the indoor environment.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Poluição do Ar em Ambientes Fechados/prevenção & controle , Fungos/crescimento & desenvolvimento , Meio Ambiente , Humanos , Umidade/prevenção & controle , Higiene , Temperatura , Estados Unidos
19.
Appl Microbiol Biotechnol ; 104(9): 3715-3727, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32172323

RESUMO

Formaldehyde is a ubiquitous carcinogenic indoor pollutant. The treatment of formaldehyde has attracted increasing social attention. Over the past few decades, an increasing number of publications have reported approaches for removing indoor formaldehyde. These potential strategies include physical adsorption, chemical catalysis, and biodegradation. Although physical adsorption is widely used, it does not really remove pollution. Chemical catalysis is very efficient but adds the risk of introducing secondary pollutants. Biological removal strategies have attracted more research attention than the first two methods, because it is more efficient, clean, and economical. Plants and bacteria are the common organisms used in formaldehyde removal. However, both have limitations and shortcomings when used alone. This review discusses the mechanisms, applications, and improvements of existing biological methods for the removal of indoor gaseous formaldehyde. A combination strategy relying on plants, bacteria, and physical adsorbents exhibits best ability to remove formaldehyde efficiently, economically, and safely. When this combination system is integrated with a heating, ventilation, air conditioning, and cooling (HVAC) system, a practical combined system can be established in formaldehyde removal. Multivariate interactions of biological and non-biological factors are needed for the future development of indoor formaldehyde removal. KEY POINTS: • Indoor gaseous formaldehyde removal is necessary especially for new residence. • Biological removal strategies have attracted increasing research attentions. • Combined system of plants, bacteria, and physical adsorbents exhibits best efficiency. • Integrated device of biological and non-biological factors will be potential practical.


Assuntos
Poluição do Ar em Ambientes Fechados/prevenção & controle , Biodegradação Ambiental , Biotecnologia/tendências , Formaldeído/isolamento & purificação , Gases/isolamento & purificação , Plantas/metabolismo , Adsorção , Ar Condicionado , Calefação , Redes e Vias Metabólicas , Ventilação
20.
Poult Sci ; 99(2): 869-878, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32036982

RESUMO

Ammonia (NH3) emission from nondigested nutrients in poultry creates additional adverse environmental impacts on soil, water, air, and health. Mitigating NH3 emission has become vital for the poultry industry to remain sustainable. As the presence of large particles in the feed stimulates the broiler gizzard to retain ingesta in the gastrointestinal tract longer and improve digestive efficiency, the inclusion of large particles in feed may lead to less nitrogen (N) and moisture content (MC) in feces such that lower NH3 production would be expected. This chamber study investigated the effects of dietary coarse corn (CC) inclusion on broiler live performance, litter characteristics, and NH3 emission. One hundred eighty female broilers (Ross 344 × 708 strains) at day 21 were randomly placed in 6 chambers with 2 dietary treatments (0% CC and 50% CC), with 3 chambers per treatment and 30 birds per chamber for 3 wks. The results showed that the 50% CC inclusion (1) decreased broiler feed intake and BW without affecting mortality-adjusted feed conversion ratio from day 21 to 42; (2) increased gizzard weight and decreased proventriculus weight; (3) decreased N content and MC in litter; and (4) decreased NH3 concentrations in the chambers, as well as NH3 emission from the chambers. Dietary CC inclusion could be an effective way to mitigate broiler litter N content and MC as well as NH3 emission.


Assuntos
Amônia/metabolismo , Galinhas/metabolismo , Esterco/análise , Zea mays , Poluição do Ar em Ambientes Fechados/análise , Poluição do Ar em Ambientes Fechados/prevenção & controle , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Fezes/química , Feminino , Moela das Aves , Nitrogênio/análise , Tamanho do Órgão , Tamanho da Partícula , Proventrículo
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