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1.
Environ Res ; 204(Pt A): 111975, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34478722

RESUMO

We used a large national cohort in Canada to assess the incidence of acute myocardial infarction (AMI) and stroke hospitalizations in association with long-term exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3). The study population comprised 2.7 million respondents from the 2006 Canadian Census Health and Environment Cohort (CanCHEC), followed for incident hospitalizations of AMI or stroke between 2006 and 2016. We estimated 10-year moving average estimates of PM2.5, NO2, and O3, annually. We used Cox proportional hazards models to examine the associations adjusting for various covariates. For AMI, each interquartile range (IQR) increase in exposure was found to be associated with a hazard ratio of 1.026 (95% CI: 1.007-1.046) for PM2.5, 1.025 (95% CI: 1.001-1.050) for NO2, and 1.062 (95% CI: 1.041-1.084) for O3, respectively. Similarly, for stroke, an IQR increase in exposure was associated with a hazard ratio of 1.078 (95% CI: 1.052-1.105) for PM2.5, 0.995 (95% CI: 0.965-1.030) for NO2, and 1.055 (95% CI: 1.028-1.082) for O3, respectively. We found consistent evidence of positive associations between long-term exposures to PM2.5, and O3, and to a lesser degree NO2, with incident AMI and stroke hospitalizations.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Infarto do Miocárdio , Ozônio , Acidente Vascular Cerebral , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Canadá/epidemiologia , Estudos de Coortes , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Humanos , Infarto do Miocárdio/induzido quimicamente , Infarto do Miocárdio/epidemiologia , Dióxido de Nitrogênio/análise , Dióxido de Nitrogênio/toxicidade , Ozônio/análise , Ozônio/toxicidade , Material Particulado/análise , Material Particulado/toxicidade , Acidente Vascular Cerebral/induzido quimicamente , Acidente Vascular Cerebral/epidemiologia
2.
Artigo em Inglês | MEDLINE | ID: mdl-34948913

RESUMO

Few studies have investigated the relationship between ambient air pollution and cardiorespiratory outcomes in Africa. A cross-sectional study comprising of 572 adults from four informal settlements in the Western Cape, South Africa was conducted. Participants completed a questionnaire adapted from the European Community Respiratory Health Survey, and the National Health and Nutrition Examination Survey questionnaire. Exposure estimates were previously modelled using Land-Use Regression for Particulate Matter (PM2.5) and Nitrogen Dioxide (NO2) at participants' homes. The median age of the participants was 40.7 years, and 88.5% were female. The median annual NO2 level was 19.7 µg/m3 (interquartile range [IQR: 9.6-23.7]) and the median annual PM2.5 level was 9.7 µg/m3 (IQR: 7.3-12.4). Logistic regression analysis was used to assess associations between outcome variables and air pollutants. An interquartile range increase of 5.12 µg/m3 in PM2.5 was significantly associated with an increased prevalence of self-reported chest-pain, [Odds ratio: 1.38 (95% CI: 1.06-1.80)], adjusting for NO2, and other covariates. The study found preliminary circumstantial evidence of an association between annual ambient PM2.5 exposure and self-reported chest-pain (a crude proxy of angina-related pain), even at levels below the South African National Ambient Air Quality Standards.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Adulto , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Poluição do Ar/análise , Poluição do Ar/estatística & dados numéricos , Estudos Transversais , Exposição Ambiental/estatística & dados numéricos , Feminino , Humanos , Dióxido de Nitrogênio/análise , Inquéritos Nutricionais , Material Particulado/análise , Material Particulado/toxicidade , África do Sul/epidemiologia
3.
BMJ ; 375: n2368, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34625469

RESUMO

OBJECTIVE: To investigate the association between changes in long term residential exposure to ambient fine particulate matter (PM2.5) and premature mortality in Canada. DESIGN: Population based quasi-experimental study. SETTING: Canada. PARTICIPANTS: 663 100 respondents to the 1996, 2001, and 2006 Canadian censuses aged 25-89 years who had consistently lived in areas with either high or low PM2.5 levels over five years preceding census day and moved during the ensuing five years. INTERVENTIONS: Changes in long term exposure to PM2.5 arising from residential mobility. MAIN OUTCOME MEASURES: The primary outcome was deaths from natural causes. Secondary outcomes were deaths from any cardiometabolic cause, any respiratory cause, and any cancer cause. All outcomes were obtained from the national vital statistics database. RESULTS: Using a propensity score matching technique with numerous personal, socioeconomic, health, and environment related covariates, each participant who moved to a different PM2.5 area was matched with up to three participants who moved within the same PM2.5 area. In the matched groups that moved from high to intermediate or low PM2.5 areas, residential mobility was associated with a decline in annual PM2.5 exposure from 10.6 µg/m3 to 7.4 and 5.0 µg/m3, respectively. Conversely, in the matched groups that moved from low to intermediate or high PM2.5 areas, annual PM2.5 increased from 4.6 µg/m3 to 6.7 and 9.2 µg/m3. Five years after moving, individuals who experienced a reduction in exposure to PM2.5 from high to intermediate levels showed a 6.8% (95% confidence interval 1.7% to 11.7%) reduction in mortality (2510 deaths in 56 025 v 4925 deaths in 101 960). A greater decline in mortality occurred among those exposed to a larger reduction in PM2.5. Increased mortality was found with exposure to PM2.5 from low to high levels, and to a lesser degree from low to intermediate levels. Furthermore, the decreases in PM2.5 exposure were most strongly associated with reductions in cardiometabolic deaths, whereas the increases in PM2.5 exposure were mostly related to respiratory deaths. No strong evidence was found for the changes in PM2.5 exposure with cancer related deaths. CONCLUSIONS: In Canada, decreases in PM2.5 were associated with lower mortality, whereas increases in PM2.5 were associated with higher mortality. These results were observed at PM2.5 levels considerably lower than many other countries, providing support for continuously improving air quality.


Assuntos
Poluição do Ar/análise , Mortalidade Prematura , Material Particulado/efeitos adversos , Adulto , Idoso , Poluição do Ar/efeitos adversos , Canadá/epidemiologia , Censos , Exposição Ambiental/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados não Aleatórios como Assunto
4.
Environ Res ; 186: 109606, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32371276

RESUMO

BACKGROUND: No previous epidemiological study has investigated the combined association of long-term ambient nitrogen dioxide (NO2) and particulate matter of diameter size-2.5 (PM2.5) exposure with asthma outcomes among schoolchildren in Africa. OBJECTIVES: This study investigated the independent and co-pollutant association of long-term exposures to ambient air pollutants on asthma-associated outcomes in a cohort of schoolchildren in the Western Cape Province of South Africa. METHODS: A total of 590 grade-4 schoolchildren residing in four informal settlements were studied. Spirometry and fractional exhaled nitric-oxide (FeNO) measurements were conducted, including a standardized questionnaire administered to caregivers at baseline and 12-months follow-up. Annual NO2 and PM2.5 levels were estimated for each child's home using land-use regression modelling. Single- and two-pollutant models were constructed to assess the independent and co-pollutant association of both air pollutants (NO2 and PM2.5) on new cases of asthma-associated outcomes adjusting-for host characteristics, indoor exposures and study area. RESULTS: The annual average concentration of PM2.5 and NO2 were 10.01µg/m3 and 16.62µg/m3 respectively, across the four study areas, and were below the local Standards of 20µg/m3 and 40µg/m3, for both pollutants, respectively. In the two-pollutant-adjusted models, an interquartile range (IQR) increase of 14.2µg/m3 in NO2 was associated with an increased risk of new onset of ocular-nasal symptoms (adjusted odds ratio-aOR: 1.63, 95% CI: 1.01-2.60), wheezing (aOR: 3.57, 95% CI: 1.18-10.92), more than two or more asthma symptom score (aOR: 1.71, 95% CI: 1.02-2.86), and airway inflammation defined as FeNO > 35 ppb (aOR: 3.10, 95% CI: 1.10-8.71), independent of PM2.5 exposures. CONCLUSION: This study provided evidence that ambient NO2 levels below local standards and international guidelines, independent of PM2.5 exposure, increases new cases of asthma-associated outcomes after 12-months.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/efeitos adversos , Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Criança , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Humanos , Dióxido de Nitrogênio/análise , Material Particulado/análise , Material Particulado/toxicidade , Estudos Prospectivos , África do Sul/epidemiologia
5.
Environ Pollut ; 260: 114023, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32018199

RESUMO

BACKGROUND: The individual effects of biological constituents of particulate matter (PM) such as fungal spores, on lung function in children are not well known. This study investigated the seasonal short-term effect of daily variation in Alternaria and Cladosporium fungal spores on lung function in schoolchildren. METHODS: This panel study evaluated 313 schoolchildren in informal settlements of the Western Cape of South Africa, exposed to spores of two commonly encountered fungi, Alternaria and Cladosporium species. The children provided forced-expiratory volume in 1-s (FEV1) and peak-expiratory flow (PEF) measurements thrice daily for two consecutive school-weeks in summer and winter. Daily PM10 levels, from a stationary ambient air quality monitor and fungal spore levels using spore traps were measured in each study area throughout the year. The effects of Alternaria and Cladosporium spores, on lung function were analysed for lag periods up to five-days, adjusting-for PM10, other pollen exposures, study area, and other host and meteorological factors. Same-day exposure-response curves were computed for both fungal species. RESULTS: There was more variability in Alternaria spores level with noticeable peaks in summer. There were consistent lag-effects for Alternaria on PEF compared to Cladosporium, with the largest PEF deficit observed in winter (mean deficit: 13.78 L/min, 95%CI: 24.34 to -3.23 L/min) per 10spores/m3 increase in Alternaria spores on lag day-2. Although there were no observable lag-effects for Alternaria and Cladosporium on FEV1, same-day effects of Cladosporium spores on FEV1 was present across both seasons. Threshold effects of Alternaria on both PEF and FEV1 deficits were apparent at levels of 100 spores/m3, but could not be explored for Cladosporium beyond the levels observed during the study. CONCLUSION: The study provides evidence for the independent effects of daily exposure to ambient fungal spores of Alternaria and Cladosporium on lung function deficits, more especially in winter for PEF.


Assuntos
Microbiologia do Ar , Cladosporium , Exposição Ambiental/estatística & dados numéricos , Esporos Fúngicos , Criança , Humanos , Estações do Ano , África do Sul
6.
Epidemiology ; 31(2): 177-183, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31714401

RESUMO

BACKGROUND: Ambient ultrafine particles (UFPs, <0.1 µm) can reach the human brain, but to our knowledge, epidemiologic studies have yet to evaluate the relation between UFPs and incident brain tumors. METHODS: We conducted a cohort study of within-city spatial variations in ambient UFPs across Montreal and Toronto, Canada, among 1.9 million adults included in multiple cycles of the Canadian Census Health and Environment Cohorts (1991, 1996, 2001, and 2006). UFP exposures (3-year moving averages) were assigned to residential locations using land-use regression models with exposures updated to account for residential mobility within and between cities. We followed cohort members for malignant brain tumors (ICD-10 codes C71.0-C71.9) between 2001 and 2016; Cox proportional hazards models (stratified by age, sex, immigration status, and census cycle) were used to estimate hazard ratios (HRs) adjusting for fine particle mass concentrations (PM2.5), nitrogen dioxide (NO2), and various sociodemographic factors. RESULTS: In total, we identified 1,400 incident brain tumors during the follow-up period. Each 10,000/cm increase in UFPs was positively associated with brain tumor incidence (HR = 1.112, 95% CI = 1.042, 1.188) after adjusting for PM2.5, NO2, and sociodemographic factors. Applying an indirect adjustment for cigarette smoking and body mass index strengthened this relation (HR = 1.133, 95% CI = 1.032, 1.245). PM2.5 and NO2 were not associated with an increased incidence of brain tumors. CONCLUSIONS: Ambient UFPs may represent a previously unrecognized risk factor for incident brain tumors in adults. Future studies should aim to replicate these results given the high prevalence of UFP exposures in urban areas.


Assuntos
Poluição do Ar , Neoplasias Encefálicas , Material Particulado , Adulto , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Neoplasias Encefálicas/epidemiologia , Canadá/epidemiologia , Cidades/epidemiologia , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Material Particulado/efeitos adversos , Material Particulado/análise , Análise Espacial
8.
Indoor Air ; 29(1): 89-100, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30339304

RESUMO

The health impact of indoor air pollution in informal settlement households has not been extensively studied in South Africa. This cross-sectional study investigated the association between asthma and common indoor exposures among schoolchildren from four informal settlements located in two municipalities in the Western Cape Province. A total of 590 children, aged 9-11 years, were recruited. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was administered to caregivers. Pulmonary function assessment included spirometry and fractional exhaled nitric oxide (FeNO). Phadiatop test for atopy was done. The prevalence of doctor-diagnosed asthma was 3.4% (n = 20) among whom only 50% were on treatment. The prevalence of current wheeze was 12.9%, and 17.6% had airway obstruction (FEV1  < lower limit of normal), while 10.2% had airway inflammation (FeNO > 35 ppb). In adjusted logistic regression models, dampness, visible mold growth, paraffin use for cooking, and passive smoking were associated with a twofold to threefold increased risk in upper and lower airway outcomes. The strongest association was that of visible mold growth with rhinitis (adjusted odds ratio-aOR 3.37, 95% CI: 1.69-6.71). Thus, there is a need for improved diagnosis of childhood asthma and Indoor Air Quality in informal settlement households.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar em Ambientes Fechados/efeitos adversos , Asma/epidemiologia , Antiasmáticos/uso terapêutico , Asma/diagnóstico , Asma/tratamento farmacológico , Criança , Estudos Transversais , Feminino , Fungos , Humanos , Masculino , Fatores de Risco , Instituições Acadêmicas , Fumar/efeitos adversos , África do Sul/epidemiologia , Espirometria , Estudantes , Inquéritos e Questionários
9.
Artigo em Inglês | MEDLINE | ID: mdl-29996511

RESUMO

Air pollution can cause many adverse health outcomes, including cardiovascular and respiratory disorders. Land use regression (LUR) models are frequently used to describe small-scale spatial variation in air pollution levels based on measurements and geographical predictors. They are particularly suitable in resource limited settings and can help to inform communities, industries, and policy makers. Weekly measurements of NO2 and PM2.5 were performed in three informal areas of the Western Cape in the warm and cold seasons 2015⁻2016. Seasonal means were calculated using routinely monitored pollution data. Six LUR models were developed (four seasonal and two annual) using a supervised stepwise land-use-regression method. The models were validated using leave-one-out-cross-validation and tested for spatial autocorrelation. Annual measured mean NO2 and PM2.5 were 22.1 μg/m³ and 10.2 μg/m³, respectively. The NO2 models for the warm season, cold season, and overall year explained 62%, 77%, and 76% of the variance (R²). The PM2.5 annual models had lower explanatory power (R² = 0.36, 0.29, and 0.29). The best predictors for NO2 were traffic related variables (major roads, bus routes). Local sources such as grills and waste burning sites appeared to be good predictors for PM2.5, together with population density. This study demonstrates that land-use-regression modelling for NO2 can be successfully applied to informal peri-urban settlements in South Africa using similar predictor variables to those performed in Europe and North America. Explanatory power for PM2.5 models is lower due to lower spatial variability and the possible impact of local transient sources. The study was able to provide NO2 and PM2.5 seasonal exposure estimates and maps for further health studies.


Assuntos
Poluentes Atmosféricos/análise , Modelos Teóricos , Dióxido de Nitrogênio/análise , Material Particulado/análise , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Áreas de Pobreza , Análise de Regressão , Estações do Ano , África do Sul
10.
Environ Pollut ; 241: 1056-1062, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30029313

RESUMO

In developing countries, noise annoyance and noise sensitivity are not commonly investigated. The present study aimed to assess the annoyance and sensitivity to noise in 364 adults living in informal settings in the Western Cape Province, South Africa and to compare with a similar study conducted in Switzerland. Compared to Switzerland, higher percentages of highly noise sensitive individuals (women: 35.1% vs 26.9%; men: 25% vs 20.5%) and people highly annoyed to road traffic noise (women: 20.5% vs 12.4%; men: 17.9% vs 11.1%) were observed in South Africa. While in South Africa women were more annoyed to neighborhood noise than in Switzerland (21.1% vs 9.4%), this was not the case among men (7.1% vs 7.8%). Multivariable logistic regression models showed that in both countries men tended to be less sensitive and less annoyed by noise. Corresponding associations with age and education were somewhat different between the countries, which may be explained by socioeconomic and environmental differences. This study indicates that noise exposure considerably affects people living in informal settlements, and noise should be considered when improving the housing conditions.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Ruído , Opinião Pública , Adulto , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Ruído dos Transportes , Características de Residência , África do Sul , Suíça , Adulto Jovem
11.
BMC Public Health ; 17(1): 712, 2017 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-28915873

RESUMO

BACKGROUND: There is evidence from existing literature that ambient air pollutant exposure in early childhood likely plays an important role in asthma exacerbation and other respiratory symptoms, with greater effect among asthmatic children. However, there is inconclusive evidence on the role of ambient air pollutant exposures in relation to increasing asthma prevalence as well as asthma induction in children. At the population level, little is known about the potential synergistic effects between pollen allergens and air pollutants since this type of association poses challenges in uncontrolled real life settings. In particular, data from sub-Sahara Africa is scarce and virtually absent among populations residing in informal residential settlements. METHODS/DESIGN: A prospective cohort study of 600 school children residing in four informal settlement areas with varying potential ambient air pollutant exposure levels in the Western Cape in South Africa is carried-out. The study has two follow-up periods of at least six-months apart including an embedded panel study in summer and winter. The exposure assessment component models temporal and spatial variability of air quality in the four study areas over the study duration using land-use regression modelling (LUR). Additionally, daily pollen levels (mould spores, tree, grass and weed pollen) in the study areas are recorded. In the panel study asthma symptoms and serial peak flow measurements is recorded three times daily to determine short-term serial airway changes in relation to varying ambient air quality and pollen over 10-days during winter and summer. The health outcome component of the cohort study include; the presence of asthma using a standardised ISAAC questionnaire, spirometry, fractional exhaled nitric-oxide (FeNO) and the presence of atopy (Phadiatop). DISCUSSION: This research applies state of the art exposure assessment approaches to characterize the effects of ambient air pollutants on childhood respiratory health, with a specific focus on asthma and markers of airway inflammation (FeNO) in South African informal settlement areas by considering also pollen counts and meteorological factors. The study will generate crucial data on air pollution and asthma in low income settings in sub-Sahara Africa that is lacking in the international literature.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/efeitos adversos , Asma/epidemiologia , Exposição Ambiental/efeitos adversos , Doenças Respiratórias/epidemiologia , Adolescente , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Alérgenos/efeitos adversos , Alérgenos/análise , Feminino , Humanos , Masculino , Conceitos Meteorológicos , Pólen/efeitos adversos , Estudos Prospectivos , Estações do Ano , África do Sul/epidemiologia
12.
J Public Health Afr ; 6(2): 420, 2015 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-28299141

RESUMO

Exaggerated sympathetic-mediated cardiovascular responses to stressful stimuli (such as cold exposure) has been linked to the development of hypertension and cardiovascular disease, which in turn has been demonstrated to predict the development of future hypertension. The aim of the present study was to test the hypothesis that enhanced change in myocardial oxygen consumption (MVO2) to cutaneous cold stress may be one potential mechanism that predisposes overweight/obese individuals in Africa to developing hypertension. The Rate-Pressure-Product (a non-invasive determinant of MVO2) was measured in normotensive young individuals aged between 18 and 25 years at baseline and during sympathetic activation elicited by cutaneous cold stimulation (CCS). Following CCS, there was a significant enhanced rate pressure product (RPP) change in overweight individuals (P = 0.019). Furthermore, multivariate regression analysis showed that body mass index, but not body weight had a significant influence on RPP variation following CCS. Thus, it can be concluded that normotensive overweight or obese individuals have an exaggerated RPP response to the CCS. However, exposure to cold may augment sympathetic reactivity in overweight/obese individuals, which may contribute to increased risk of developing myocardial dysfunction, even in young normotensive individuals.

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