Paulo Hilário Nascimento Saldiva

Mortality risk attributable to high and low ambient temperature: a multicountry observational study.

Summary Background Although studies have provided estimates of premature deaths attributable to either heat or cold in selected countries, none has so far offered a systematic assessment across the whole temperature range in populations exposed to different climates. We aimed to quantify the total mortality burden attributable to non-optimum ambient temperature, and the relative contributions from heat and cold and from moderate and extreme temperatures. Methods We collected data for 384 locations in Australia, Brazil, Canada, China, Italy, Japan, South Korea, Spain, Sweden, Taiwan, Thailand, UK, and USA. We fitted a standard time-series Poisson model for each location, controlling for trends and day of the week. We estimated temperature–mortality associations with a distributed lag non-linear model with 21 days of lag, and then pooled them in a multivariate metaregression that included country indicators and temperature average and range. We calculated attributable deaths for heat and cold, defined as temperatures above and below the optimum temperature, which corresponded to the point of minimum mortality, and for moderate and extreme temperatures, defined using cutoffs at the 2·5th and 97·5th temperature percentiles. Findings We analysed 74 225 200 deaths in various periods between 1985 and 2012. In total, 7·71% (95% empirical CI 7·43–7·91) of mortality was attributable to non-optimum temperature in the selected countries within the study period, with substantial differences between countries, ranging from 3·37% (3·06 to 3·63) in Thailand to 11·00% (9·29 to 12·47) in China. The temperature percentile of minimum mortality varied from roughly the 60th percentile in tropical areas to about the 80–90th percentile in temperate regions. More temperature-attributable deaths were caused by cold (7·29%, 7·02–7·49) than by heat (0·42%, 0·39–0·44). Extreme cold and hot temperatures were responsible for 0·86% (0·84–0·87) of total mortality. Interpretation Most of the temperature-related mortality burden was attributable to the contribution of cold. The effect of days of extreme temperature was substantially less than that attributable to milder but non-optimum weather. This evidence has important implications for the planning of public-health interventions to minimise the health consequences of adverse temperatures, and for predictions of future effect in climate-change scenarios. Funding UK Medical Research Council.

Lung Pathology in Fatal Novel Human Influenza A (H1N1) Infection

RATIONALE There are no reports of the systemic human pathology of the novel swine H1N1 influenza (S-OIV) infection. OBJECTIVES The autopsy findings of 21 Brazilian patients with confirmed S-OIV infection are presented. These patients died in the winter of the southern hemisphere 2009 pandemic, with acute respiratory failure. METHODS Lung tissue was submitted to virologic and bacteriologic analysis with real-time reverse transcriptase polymerase chain reaction and electron microscopy. Expression of toll-like receptor (TLR)-3, IFN-gamma, tumor necrosis factor-alpha, CD8(+) T cells and granzyme B(+) cells in the lungs was investigated by immunohistochemistry. MEASUREMENTS AND MAIN RESULTS Patients were aged from 1 to 68 years (72% between 30 and 59 yr) and 12 were male. Sixteen patients had preexisting medical conditions. Diffuse alveolar damage was present in 20 individuals. In six patients, diffuse alveolar damage was associated with necrotizing bronchiolitis and in five with extensive hemorrhage. There was also a cytopathic effect in the bronchial and alveolar epithelial cells, as well as necrosis, epithelial hyperplasia, and squamous metaplasia of the large airways. There was marked expression of TLR-3 and IFN-gamma and a large number of CD8(+) T cells and granzyme B(+) cells within the lung tissue. Changes in other organs were mainly secondary to multiple organ failure. CONCLUSIONS Autopsies have shown that the main pathological changes associated with S-OIV infection are localized to the lungs, where three distinct histological patterns can be identified. We also show evidence of ongoing pulmonary aberrant immune response. Our results reinforce the usefulness of autopsy in increasing the understanding of the novel human influenza A (H1N1) infection.

The Impact of Sugar Cane–Burning Emissions on the Respiratory System of Children and the Elderly

We analyzed the influence of emissions from burning sugar cane on the respiratory system during almost 1 year in the city of Piracicaba in southeast Brazil. From April 1997 through March 1998, samples of inhalable particles were collected, separated into fine and coarse particulate mode, and analyzed for black carbon and tracer elements. At the same time, we examined daily records of children (< 13 years of age) and elderly people (> 64 years of age) admitted to the hospital because of respiratory diseases. Generalized linear models were adopted with natural cubic splines to control for season and linear terms to control for weather. Analyses were carried out for the entire period, as well as for burning and nonburning periods. Additional models were built using three factors obtained from factor analysis instead of particles or tracer elements. Increases of 10.2 μg/m3 in particles ≥ 2.5 μm/m3 aerodynamic diameter (PM2.5) and 42.9 μg/m3 in PM10 were associated with increases of 21.4% [95% confidence interval (CI), 4.3–38.5] and 31.03% (95% CI, 1.25–60.21) in child and elderly respiratory hospital admissions, respectively. When we compared periods, the effects during the burning period were much higher than the effects during nonburning period. Elements generated from sugar cane burning (factor 1) were those most associated with both child and elderly respiratory admissions. Our results show the adverse impact of sugar cane burning emissions on the health of the population, reinforcing the need for public efforts to reduce and eventually eliminate this source of air pollution.

Outdoor particulate matter exposure and lung cancer: a systematic review and meta-analysis.

BACKGROUND Particulate matter (PM) in outdoor air pollution was recently designated a Group I carcinogen by the International Agency for Research on Cancer (IARC). This determination was based on the evidence regarding the relationship of PM2.5 and PM10 to lung cancer risk; however, the IARC evaluation did not include a quantitative summary of the evidence. OBJECTIVE Our goal was to provide a systematic review and quantitative summary of the evidence regarding the relationship between PM and lung cancer. METHODS We conducted meta-analyses of studies examining the relationship of exposure to PM2.5 and PM10 with lung cancer incidence and mortality. In total, 18 studies met our inclusion criteria and provided the information necessary to estimate the change in lung cancer risk per 10-μg/m3 increase in exposure to PM. We used random-effects analyses to allow between-study variability to contribute to meta-estimates. RESULTS The meta-relative risk for lung cancer associated with PM2.5 was 1.09 (95% CI: 1.04, 1.14). The meta-relative risk of lung cancer associated with PM10 was similar, but less precise: 1.08 (95% CI: 1.00, 1.17). Estimates were robust to restriction to studies that considered potential confounders, as well as subanalyses by exposure assessment method. Analyses by smoking status showed that lung cancer risk associated with PM2.5 was greatest for former smokers [1.44 (95% CI: 1.04, 1.22)], followed by never-smokers [1.18 (95% CI: 1.00, 1.39)], and then current smokers [1.06 (95% CI: 0.97, 1.15)]. In addition, meta-estimates for adenocarcinoma associated with PM2.5 and PM10 were 1.40 (95% CI: 1.07, 1.83) and 1.29 (95% CI: 1.02, 1.63), respectively. CONCLUSION The results of these analyses, and the decision of the IARC Working Group to classify PM and outdoor air pollution as carcinogenic (Group 1), further justify efforts to reduce exposures to air pollutants that can arise from many sources.

Health effects of air pollution exposure on children and adolescents in São Paulo, Brazil

Children and adolescents have been considered more susceptible to the effects of air pollution than adults. In order to investigate the responses of children of different ages to air pollution exposure, daily records of hospital admissions for children in five age groups (equal or less than 2 years of age, 3–5, 6–13, 14–19, and all ages together, i.e., from 0–19 years of age) were obtained from January 1993 to November 1997 in São Paulo, Brazil, and were compared to daily records of PM10, O3, SO2, CO and NO2 concentrations in ambient air. For each age group a generalized additive Poisson regression was fitted controlling for smooth functions of time, temperature, humidity, and days of the week, with an additional indicator for holidays. Polynomial distributed lag models were used to estimate the 7‐day cumulative effect of each pollutant.

Global variation in the effects of ambient temperature on mortality: a systematic evaluation

Background: Studies have examined the effects of temperature on mortality in a single city, country, or region. However, less evidence is available on the variation in the associations between temperature and mortality in multiple countries, analyzed simultaneously. Methods: We obtained daily data on temperature and mortality in 306 communities from 12 countries/regions (Australia, Brazil, Thailand, China, Taiwan, Korea, Japan, Italy, Spain, United Kingdom, United States, and Canada). Two-stage analyses were used to assess the nonlinear and delayed relation between temperature and mortality. In the first stage, a Poisson regression allowing overdispersion with distributed lag nonlinear model was used to estimate the community-specific temperature-mortality relation. In the second stage, a multivariate meta-analysis was used to pool the nonlinear and delayed effects of ambient temperature at the national level, in each country. Results: The temperatures associated with the lowest mortality were around the 75th percentile of temperature in all the countries/regions, ranging from 66th (Taiwan) to 80th (UK) percentiles. The estimated effects of cold and hot temperatures on mortality varied by community and country. Meta-analysis results show that both cold and hot temperatures increased the risk of mortality in all the countries/regions. Cold effects were delayed and lasted for many days, whereas heat effects appeared quickly and did not last long. Conclusions: People have some ability to adapt to their local climate type, but both cold and hot temperatures are still associated with increased risk of mortality. Public health strategies to alleviate the impact of ambient temperatures are important, in particular in the context of climate change.

Air pollution from biomass burning and asthma hospital admissions in a sugar cane plantation area in Brazil

Objective: To evaluate the association between the total suspended particles (TSPs) generated from preharvest sugar cane burning and hospital admission due to asthma (asthma hospital admissions) in the city of Araraquara. Design: An ecological time-series study. Total daily records of asthma hospital admissions (ICD 10th J15) were obtained from one of the main hospitals in Araraquara, São Paulo State, Brazil, from 23 March 2003 to 27 July 2004. The daily concentration of TSP (μg/m3) was obtained using Handi-vol equipment (Energética, Brazil) placed in downtown Araraquara. The local airport provided the daily mean figures of temperature and humidity. The daily number of asthma hospital admissions was considered as the dependent variable in Poisson’s regression models and the daily concentration of TSP was considered the independent variable. The generalised linear model with natural cubic spline was adopted to control for long-time trend. Linear terms were used for weather variables. Results: TSP had an acute effect on asthma admissions, starting 1 day after TSP concentrations increased and remaining almost unchanged for the next four days. A 10 μg/m3 increase in the 5-day moving average (lag1–5) of TSP concentrations was associated with an increase of 11.6% (95% CI 5.4 to 17.7) in asthma hospital admissions. Conclusion: Increases in TSP concentrations were definitely associated with asthma hospital admissions in Araraquara and, despite using sugar cane alcohol to reduce air pollution from automotive sources in large Brazilian urban centres, the cities where sugar cane is harvested pay a high toll in terms of public health.

Influence of socioeconomic conditions on air pollution adverse health effects in elderly people: an analysis of six regions in São Paulo, Brazil

Study objective: To evaluate if the effects of particulate matter (PM10) on respiratory mortality of elderly people are affected by socioeconomic status. Design: Time series studies. The daily number of elderly respiratory deaths were modelled in generalised linear Poisson regression models controlling for long term trend, weather, and day of the week, from January 1997 to December 1999, in six different regions of São Paulo City, Brazil. The regions were defined according to the proximity of air pollution monitoring stations. Three socioeconomic indicators were used: college education, monthly income, and housing. Main results: For a 10 μg/m3 increase in PM10, the percentage increase in respiratory mortality varied from 1.4% (95% CI 5.9 to 8.7) to 14.2% (95% CI 0.4 to 28.0). The overall percentage increase in the six regions was 5.4% (95% CI 2.3 to 8.6). The effect of PM10 was negatively correlated with both percentage of people with college education and high family income, and it was positively associated with the percentage of people living in slums. Conclusions: These results suggest that socioeconomic deprivation represents an effect modifier of the association between air pollution and respiratory deaths.

Particulate Urban Air Pollution Affects the Functional Morphology of Mouse Placenta

Abstract In humans, adverse pregnancy outcomes (low birth weight, prematurity, and intrauterine growth retardation) are associated with exposure to urban air pollution. Experimental data have also shown that such exposure elicits adverse reproductive outcomes. We hypothesized that the effects of urban air pollution on pregnancy outcomes could be related to changes in functional morphology of the placenta. To test this, future dams were exposed during pregestational and gestational periods to filtered or nonfiltered air in exposure chambers. Placentas were collected from near-term pregnancies and prepared for microscopical examination. Fields of view on vertical uniform random tissue slices were analyzed using stereological methods. Volumes of placental compartments were estimated, and the labyrinth was analyzed further in terms of its maternal vascular spaces, fetal capillaries, trophoblast, and exchange surface areas. From these primary data, secondary quantities were derived: vessel calibers (expressed as diameters), trophoblast thickness (arithmetic mean), and total and mass-specific morphometric diffusive conductances for oxygen of the intervascular barrier. Two-way analysis of variance showed that both periods of exposure led to significantly smaller fetal weights. Pregestational exposure to nonfiltered air led to significant increases in fetal capillary surface area and in total and mass-specific conductances. However, the calibers of maternal blood spaces were reduced. Gestational exposure to nonfiltered air was associated with reduced volumes, calibers, and surface areas of maternal blood spaces and with greater fetal capillary surfaces and diffusive conductances. The findings indicate that urban air pollution affects placental functional morphology. Fetal weights are compromised despite attempts to improve diffusive transport across the placenta.

Association between air pollution and ischemic cardiovascular emergency room visits

This study observed the relationship between air pollutants and ischemic cardiac diseases such as angina and acute myocardial infarction in a representative cardiovascular center emergency room in São Paulo, Brazil. Daily emergency room admissions to the Institute of the Heart of the University of São Paulo, as well as data concerning daily air pollutant levels and meteorological variables, were collected from January 1994 to August 1995. Generalized additive Poisson regressions were fitted to the logarithm of the expected values of total emergency room visits due to angina or acute myocardial infarction, controlling for smooth functions of season and weather and indicators for days of the week. All investigated pollutants were positively associated with ischemic cardiovascular disease emergency room visits, and the time lags were relatively short, but only CO presented an effect that was statistically significant. An interquartile range increase in CO was associated with an increase of 6.4% (95% CI: 0.7-12.1) in daily angina or acute myocardial infarction emergency room visits. This result did not change when estimates were done using linear models and natural cubic splines. This study showed that air pollution has a role in cardiovascular morbidity in São Paulo, reinforcing the necessity for air pollutant emission-controlling polices in urban areas.