Exercising under particulate matter exposure: Providing theoretical support for lung deposition and its relationship with COVID-19.

The aim of the present study was to investigate lung particulate matter (PM) deposition during endurance exercise and provide a new insight concerning how SARS-CoV-2 could be carried into the respiratory tract. The anatomical and physiological characteristics of the Human Respiratory Tract model were considered for modeling the lung PM deposition during exercise. The Monte Carlo method was performed to randomly generate different values of PM concentrations (1.0, 2.5, and 10.0 µm), minute ventilation, and duration of exercise at moderate, heavy, and severe exercise intensity domains. Compared to moderate and severe intensities, during heavy exercise (75-115 L‧min-1, duration of 10.0-60.0 min) there is greater lung deposition in the bronchiolar region (p < 0.01). In turn, there is greater deposition per minute of exercise at the severe intensity domain (115.0-145.0 L‧min-1, duration of 10.0-20.0 min, p < 0.01). Considering that SARs-CoV-2 could be adsorbed on the particles, exercising under PM exposure, mainly at the severe domain, could be harmful concerning the virus. In conclusion, beyond the traditional minute ventilation assumption, there is a time vs intensity dependence for PM deposition, whereby the severe domain presents greater deposition per minute of exercise. The results observed for PM deposition are alarming since SARs-CoV-2 could be adsorbed by particles and carried into the deeper respiratory tract.

Sensitivity analysis of the WATER9 model: emissions of odorous compounds from passive liquid surfaces present in wastewater treatment plants.

Empirical mathematical models have been frequently used to estimate emissions and to act in the prevention of possible impacts from odorous compounds. Based on the regulatory WATER9 model, the present study had the aim to evaluate the deviations originating from the simplification of using the effective diameter (in contrast to the conceptually appropriate use of the linear physical fetch) as fetch parameter in the calculation of the global mass transfer coefficient at passive liquid surfaces at wastewater treatment plants (WWTPs). The present analysis incorporated the influence of different values of wind velocity, molecular diffusivity and Henry's Law constant. The analyses for the calculation of the mass transfer coefficients were developed for 1,000 wind speeds, chosen using the Monte Carlo method, three WWTPs and three compounds of environmental relevance, spanning different behaviour regarding their volatilisation. The wind speed had a direct influence on the deviations for all types of compounds analysed. However, this parameter was found to be more representative for the compounds whose volatilisation is limited by conditions in the liquid phase. Furthermore, the deviations for the calculation of the mass transfer coefficient arising from the use of the effective diameter as fetch parameter were significantly larger for liquid phase-dominated compounds, compared to gas phase-dominated compounds. Comparison against available experimental data confirm that the use of the effective diameter as the fetch parameter makes the model predictions further depart from the experimental values. The present analysis shows that, for a varied range of wind speed and WWTP configurations, the use of the actual physical fetch shall be preferred over the use of the effective diameter in emission models for WWTPs, so as to avoid the introduction of potentially large systematic deviations.

Investigation of rainwater contamination sources in the southern part of Brazil.

Rainwater quality is influenced by air pollutants and can affect sensitive ecosystems. This study was conducted to identify the sources of rainwater contamination in a receptor investigated in the southern part of Brazil. A total of 22 rainwater samples were collected at Florianópolis, Brazil. The sampling station is influenced by continental emissions (soil resuspension, traffic emissions and combustion) and marine aerosols. Over the sampling period, the average pH and electrical conductivity (EC) of the precipitation was found to be 4.97 +/- 0.41 and 14.68 microS cm(-1) +/- 13.47, respectively. In addition topH and EC, ions and trace metals in the collected rainwater were quantified. The results were investigated by a combination of techniques including principal component analysis (PCA), a back trajectory model and other statistical and graphical interpretation methodologies. A PCA showed that Cl(-), Na+, Mg2+ and part of the K+ and SO4(2-) content were mainly contributed by marine aerosols, whereas the contribution from continental sources (combustion, traffic emissions and other urban activities) was dominant in the content of NO3(-) and part of the SO4(2-) and Mn content. Soil resuspension was responsible for the concentrations of most of the trace metals (apart from Mn) and Ca2+ in the rainwater. An inverse correlation among the elemental concentrations, amount of rainfall and wind speed was observed. The northern transport pathway was identified as being associated with high concentrations of NO3(-) and slightly decreased pH values. However, the low standard deviation observed for the pH values during the sampling campaign also showed a small variation in the data, suggesting that the acidity is most probably being constantly sourced from a natural origin, such as organic acids.

Thermal Comfort Conditions and Mortality in Brazil.

Conventional temperature-based approaches often overlook the intricate nature of thermal stress experienced by individuals. To address this limitation, climatologists have developed thermal indices-composite measures designed to reflect the complex interaction of meteorological factors influencing human perception of temperature. Our study focuses on Brazil, estimating the association between thermal comfort conditions and mortality related to respiratory and circulatory diseases. We examined four distinct thermal indices: the discomfort index (DI), net effective temperature (NET), humidex (H), and heat index (HI). Analyzing a comprehensive dataset of 2,872,084 deaths from 2003 to 2017, we found significant variation in relative risk (RR) based on health outcomes, exposure lag, percentile of exposure, sex/age groups, and specific thermal indices. For example, under high exposure conditions (99th percentile), we observed that the shorter lags (3, 5, 7, and 10) had the most robust effects on all-cause mortality. For example, under lag 3, the pooled national results for the overall population (all ages and sexes) indicate an increased risk of all-cause mortality, with an RR of 1.17 (95% CI: 1.13; 1.122) for DI, 1.15 (95% CI: 1.12; 1.17) for H, 1.15 (95% CI: 1.09; 1.21) for HI, and 1.18 (95% CI: 1.13; 1.22) for NET. At low exposure levels (1st percentile), all four distinct thermal indices were linked to an increase in all-cause mortality across most sex and age subgroups. Specifically, for lag 20, we observed an estimated RR of 1.19 (95% CI: 1.14; 1.23) for DI, 1.12 (95% CI: 1.08; 1.16) for H, 1.17 (95% CI: 1.12; 1.22) for HI, and 1.18 (95% CI: 1.14; 1.23) for NET. These findings have important implications for policymakers, guiding the development of measures to minimize climate change's impact on public health in Brazil.

Ambient air pollution and low birth weight in Brazil: A nationwide study of more than 10 million births between 2001 and 2018.

Low birth weight (LBW) is a global health concern. While it is commonly associated with maternal health and behavior, exposure to ambient air pollution, can also play a role in contributing to LBW. In Brazil, where diverse environmental conditions and regional disparities exist, assessing the impact of ambient air pollution on LBW becomes particularly pertinent. To our knowledge, there is a gap in the existing literature, as no previous study has specifically investigated the relationship between ambient air pollution and LBW nationwide in Brazil. This study aims to fill this gap by examining the association between ambient air pollution and LBW in each trimester of pregnancy across the Brazilian states. In this work, birth data from January 1, 2001, to December 31, 2018 has been used. We utilized logistic regression models to estimate the odds ratio (OR) for low birth weight (LBW) associated with ambient air pollution (PM2.5, NO2, and O3) during each trimester of pregnancy (1st to 3rd trimester) across all 27 Brazilian states in our nationwide case-control study. We adjusted our model for several variables, including ambient temperature, relative humidity, and socioeconomic status (SES) variables at the individual level. We also conducted effect modification analyses by infant sex, mother's age, and the number of prenatal visits. Our study comprises over 10,213,144 birth records nationwide. Of these, 479,204 (4.92%) infants were included as cases of LBW. Our results indicate positive associations between PM2.5 and LBW, mainly in the Southern region. For example, in the state of Santa Catarina (South region), ORs were 1.003 (95% CI: 1.002, 1.004), 1.003 (95% CI: 1.002, 1.004), and 1.005 (95% CI: 1.003, 1.007) for the 1st, 2nd, and 3rd trimesters of exposure, respectively. NO2 had a robust association with LBW in the Northern and Northeastern states, including the state of Amapá (North region, where the Amazon Forest is located) with ORs of 1.377 (95% CI: 1.010, 1.878), 1.390 (95% CI: 1.020, 1.894), and 1.747 (95% CI: 1.297, 2.352) for the 1st, 2nd, and 3rd trimesters of exposure, respectively. Similarly, O3 had a robust association in the North and Midwest states, as observed in the state of Amapá with ORs of 1.033 (95% CI: 1.012, 1.054), and 1.033 (95% CI: 1.013, 1.053) for the 2nd, and 3rd trimesters, respectively. In the stratified analysis, boys were more vulnerable than girls, and the lower number of prenatal visits was associated with higher OR. Our findings are essential to the development of guidelines to prevent maternal exposure and protection of newborns in Brazil. This study provides valuable insights for region-specific strategies to improve maternal and neonatal health.

Particulate matter pollution and non-targeted analysis of polar compounds in three regions of Brazil.

Atmospheric Particulate Matter (PM) is a pollutant with diverse origins, exhibiting varying chemical compositions, and undergoes several molecular transformations in the atmosphere. In this study, PM samples (PM2.5, PM10 and TSP) were collected in five Brazilian cities (Camboriú-SC; Catalão-GO; Florianópolis-SC; Limeira-SP and Novo Hamburgo-RS) during the four seasons of the year. Analysis of Variance (ANOVA) was used to evaluate the differences between each city and season in PM concentration. PM10 average concentrations were higher in the city of Limeira, compared to the other (ANOVA p-values and Tukey's test). Moreover, Tukey's test demonstrated differences between the average PM10 concentrations in summer and winter. Regarding TSP and PM2.5, Tukey's test showed differences between winter and warm seasons (spring and summer). Moreover, polar compounds from the samples collected in the summer (February) and winter (August) periods were analyzed (Ultra-High-Performance Liquid Chromatography coupled to a Quadrupole Time-of-Flight Mass Spectrometer) following a non-targeted approach and annotated. This is the first study to carry out this type of analysis in these five Brazilian cities. Despite the differences in PM concentrations, profiles of polar organic compounds, showed similarities between samples/and, in general, the same compounds were present, albeit with different intensities. The annotated compounds are associated with vehicle emissions and plastics, which are considered important global air polluters. Therefore, there is an urgent necessity for comprehensive studies aimed at investigating the non-targeted compounds existing in the atmosphere. Such research can provide invaluable insights to policymakers, enabling them to formulate effective guidelines and policies to mitigate particulate matter concentration and enhance overall air quality.

Regulating light-duty vehicle emissions: an overview of US, EU, China and Brazil programs and its effect on air quality.

This paper reviews the progress and effectiveness of Programs to Control Vehicle Emissions (PCVEs), comparing the experiences in the United States (US), European Union (EU), China, and Brazil. We present a timeline comparison of updates and differences in standards for light-duty vehicle (LDV) compliance. We then review the benefits of controlling LDV emissions on air quality, derived from previous relevant studies. Emission standards have been increasingly restricted in all evaluated PCVEs. However, some technical aspects such as dynamometer test cycles, re-testing structure of environmental protection agency, homogeneity of new and in-use vehicles inspection and maintenance, on-board diagnostics requirements are more consolidated in the US. Previous studies at different scales show the success of PCVEs in reducing vehicle emissions and air pollutant concentrations in the US, EU, China, and Brazil. Despite PCVEs has been achieving relative success, vehicular emissions are still a major threat to air quality around the world, especially in developing countries or ascending economies whose fleet grows dramatically. In places where the air quality standards recommended by the World Health Organization (WHO) are violated, it would be required the implementation of more stringent regulations with a well-designed, and homogeneous compliance policy over regional and national territories. This work contributes to clarifying the current challenges and successful experiences on regulating vehicular emissions worldwide. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10098-021-02238-1.

Socioeconomic development role in hospitalization related to air pollution and meteorology: A study case in southern Brazil.

Air pollution is one of the foremost environmental threats to human health. However, the meteorological and social factors that lead to respiratory and cardiovascular diseases have not been fully elucidated. In this study, we use Principal Component Analysis and Generalized Linear Model (PCA-GLM) to investigate the combined effect of socioeconomic development and air pollution on cardiorespiratory hospitalization in southern Brazil. This region has the highest rates of hospitalization by cardiorespiratory diseases in the country. We analyze three main sources of data: (i) air pollutants density from TROPOMI/Sentinel-5p satellite; (ii) temperature, humidity, and planetary boundary layer height (PBLH) modeled with the Weather Research Forecast model; and (iii) hospitalization by cardiorespiratory diseases obtained from the Brazilian National Health System. We estimate the Relative Risk (RR) using the PCA-GLM coefficients and interquartile variations of air pollutants density and meteorological parameters. Our results show that the population living in colder and drier municipalities is more prone to cardiorespiratory hospitalization. Regarding respiratory hospitalization, municipalities with lower socioeconomic development are more sensitive to meteorology and pollution variability than highly developed ones. In less developed municipalities, we observe the highest rates of cardiorespiratory hospitalization even if air pollution is low, which we interpret in terms of higher vulnerability. The RR analysis suggests that air pollution is an important environmental risk to cardiovascular diseases and respiratory diseases is more sensitive to air pollution and meteorology than cardiovascular ones. Our findings corroborate the mounting evidence that social vulnerability is a significant factor affecting the increase of cardiorespiratory hospitalization in the world.

The novel Outer Plug Standardization (OPS) calibration strategy applied in a new method for the high-throughput determination of Cl-, NO3- and SO4-2 in rainwater samples.

This paper presents the Outer Plug Standardization - OPS, a novel technique as an alternative for the classic internal standardization using multiple injection in capillary zone electrophoresis is proposed herein. This technique was applied in a new method for the determination of chloride, nitrate and sulfate in rainwater samples. After the injection accuracy was tested and proved to be a minor error source (average 1.26% RSD), the OPS was applied and it improved the intra-day and inter-day precision of the analytical method by 32.5% and 24.7%, respectively. Using a capillary with effective length of 23.5 cm the electrophoretic separation of the three inorganic anions could be achieved in <1 min, with detection limits of 0.05, 0.09 and 0.11 mg L-1 for chloride, nitrate and sulfate, respectively. Also, the statistical t-test was applied to the results obtained for 82 rainwater samples that were collected and analyzed applying both the method developed in this study and the official APHA 4140 method where no statistical difference was noted within a 95% confidence level.

Carbon biofixation and lipid composition of an acidophilic microalga cultivated on treated wastewater supplied with different CO2 levels.

This study evaluated productivity, CO2 biofixation, and lipid content in biomass of the acidophilic microalga Chlamydomonas acidophila LAFIC-004 cultivated with five different carbon dioxide concentrations. The influence of carbon dioxide concentration on nutrient removal and pH was also investigated. Treated wastewater (secondary effluent) was used as culture medium. Five experimental setups were tested: T-0% - injection of atmospheric air (0.038% CO2), T-5% (5% CO2), T-10% (10% CO2), T-15% (15% CO2) and T-20% (20% CO2). The T-5% and T-10% experiments showed the highest values of productivity and CO2 biofixation, and maximum biomass dry weight was 0.48 ± 0.02 and 0.51 ± 0.03 g L-1, respectively. This acidophilic microalga proved to be suitable for carbon biofixation and removal of nutrients from secondary effluent of wastewater treatment plants with high CO2 concentration. All assays were performed without pH control. This microalga species presented high lipid content. However, fatty acid methyl esters (FAME) are not suitable for biodiesel use.

An analysis of error propagation in AERMOD lateral dispersion using Round Hill II and Uttenweiller experiments in reduced averaging times.

Dispersion modelling was proved by researchers that most part of the models, including the regulatory models recommended by the Environmental Protection Agency of the United States (AERMOD and CALPUFF), do not have the ability to predict under complex situations. This article presents a novel evaluation of the propagation of errors in lateral dispersion coefficient of AERMOD with emphasis on estimate of average times under 10 min. The sources of uncertainty evaluated were parameterizations of lateral dispersion ([Formula: see text]), standard deviation of lateral wind speed ([Formula: see text]) and processing of obstacle effect. The model's performance was tested in two field tracer experiments: Round Hill II and Uttenweiller. The results show that error propagation from the estimate of [Formula: see text] directly affects the determination of [Formula: see text], especially in Round Hill II experiment conditions. After average times are reduced, errors arise in the parameterization of [Formula: see text], even after observation assimilations of [Formula: see text], exposing errors on Lagrangian Time Scale parameterization. The assessment of the model in the presence of obstacles shows that the implementation of a plume rise model enhancement algorithm can improve the performance of the AERMOD model. However, these improvements are small when the obstacles have a complex geometry, such as Uttenweiller.

Preselection test of jury for improvement of olfactometric certification efficiency.

To certificate an olfactometric jury, laboratories usually follow up the panelist screening methodology described in the European Standard EN 13725/2003. The procedure takes a lot of time, labour and money. In laboratory routine of LCQAr - Laboratory of Air Quality Control, of Federal University of Santa Catarina, Brazil, it was found that the efficiency of jury approvals used to be as low as around 30%. In order to improve the efficiency, a quick preselection test was proposed and tried for late certification recommended by EN 13725. The methodology to create the preselection test was based on the conceptions of the standards EN 13725 (CEN, 2003), ASTM 679 (2011) and ASTM 544 (2010). In the trial test, 31 volunteers participated and then screened according to the EN13725 standard. It was verified that the efficiency increased to 46% from about 30% after the introduction of the preselection test. The experiments were conducted at LCQAr, with the contribution of Water Research Centre of University of New South Wales, Australia.