Continuous exposure to ambient air pollution and chronic diseases: prevalence, burden, and economic costs.

Studies that assess the connection between the prevalence of chronic diseases and continuous exposure to air pollution are scarce in developing countries, mainly due to data limitations. Largely overcoming data limitations, this study aimed to investigate the association between the likelihood of reporting a set of chronic diseases (diabetes, cancer, stroke and myocardial infarction, asthma, and hypertension) and continuous exposure to carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and coarse particulate matter (PM10). Using the estimated associations, the disease burden and economic costs of continuous exposure to air pollutants were also approximated. A 2011 Health Equity Assessment and Response Tool survey from Tehran, Iran, was used in the main analyses. A sample of 67,049 individuals who had not changed their place of residence for at least 2 years before the survey and reported all relevant socioeconomic information was selected. The individuals were assigned with the average monthly air pollutant levels of the nearest of 16 air quality monitors during the 2 years leading to the survey. Both single- and multi-pollutant analyses were conducted. The country's annual household surveys from 2002 to 2011 were used to calculate the associated economic losses. The single-pollutant analysis showed that a one-unit increase in monthly CO (ppm), NO2 (ppb), O3 (ppb), and PM10 (µg/m3) during the 2 years was associated with 751 [confidence interval (CI): 512-990], 18 (CI: 12-24), 46 (CI: -27-120), and 24 (CI: 13-35) more reported chronic diseases in 100,000, respectively. The disease-specific analyses showed that a unit change in average monthly CO was associated with 329, 321, 232, and 129 more reported cases of diabetes, hypertension, stroke and myocardial infarction, and asthma in 100,000, respectively. The measured associations were greater in samples with older individuals. Also, a unit change in average monthly O3 was associated with 21 (in 100,000) more reported cases of asthma. The multi-pollutant analyses confirmed the results from single-pollutant analyses. The supplementary analyses showed that a one-unit decrease in monthly CO level could have been associated with about 208 (CI: 147-275) years of life gained or 15.195 (CI: 10.296-20.094) thousand US dollars (USD) in life-time labor market income gained per 100,000 30-plus-year-old Tehranis.

Study of the Effects of Air Pollutants on Human Health Based on Baidu Indices of Disease Symptoms and Air Quality Monitoring Data in Beijing, China.

There is an increasing body of evidence showing the impact of air pollutants on human health such as on the respiratory, and cardio- and cerebrovascular systems. In China, as people begin to pay more attention to air quality, recent research focused on the quantitative assessment of the effects of air pollutants on human health. To assess the health effects of air pollutants and to construct an indicator placing emphasis on health impact, a generalized additive model was selected to assess the health burden caused by air pollution. We obtained Baidu indices (an evaluation indicator launched by Baidu Corporation to reflect the search popularity of keywords from its search engine) to assess daily query frequencies of 25 keywords considered associated with air pollution-related diseases. Moreover, we also calculated the daily concentrations of major air pollutants (including PM10, PM2.5, SO2, O3, NO2, and CO) and the daily air quality index (AQI) values, and three meteorological factors: daily mean wind level, daily mean air temperature, and daily mean relative humidity. These data cover the area of Beijing from 1 March 2015 to 30 April 2017. Through the analysis, we produced the relative risks (RRs) of the six main air pollutants for respiratory, and cardio- and cerebrovascular diseases. The results showed that O3 and NO2 have the highest health impact, followed by PM10 and PM2.5. The effects of any pollutant on cardiovascular diseases was consistently higher than on respiratory diseases. Furthermore, we evaluated the currently used AQI in China and proposed an RR-based index (health AQI, HAQI) that is intended for better indicating the effects of air pollutants on respiratory, and cardio- and cerebrovascular diseases than AQI. A higher Pearson correlation coefficient between HAQI and RRTotal than that between AQI and RRTotal endorsed our efforts.

Improving risk assessment approaches for chemicals with both endogenous and exogenous exposures.

To conduct risk assessments of exogenous chemicals for which there are also endogenous exposures, knowledge of the chemistry and biology of both types of exposures needs to be integrated into problem formulation and carried through to risk characterization. This issue is framed in a risk assessment context, highlighting the importance of quantifying increments of dose from all sources of the same or similar chemicals interacting with biological targets; understanding the influence of endogenous chemical concentrations on disease risk; and assessing total dose to targets in evaluating risk from incremental environmental exposures. Examples of recent assessments illustrate the importance of addressing this issue. Evaluations of data on blood or organ concentrations of ammonia, methanol, formaldehyde, acetaldehyde, and three gaseous signaling molecules (hydrogen sulfide, carbon monoxide, and nitric oxide) provide examples where current data are already informing perspectives on relative exposures at the portal of entry and systemically. To facilitate quality risk assessments of exogenous chemicals with endogenous exposures, a series of specific questions are presented that need to be addressed in systematic review to enhance problem formulation, improve the development of holistic conceptual models, and to facilitate the identification of priority data needs for improving risk assessments.

Prenatal Household Air Pollution Alters Cord Blood Mononuclear Cell Mitochondrial DNA Copy Number: Sex-Specific Associations.

BACKGROUND: Associations between prenatal household air pollution (HAP) exposure or cookstove intervention to reduce HAP and cord blood mononuclear cell (CBMC) mitochondrial deoxyribonucleic acid copy number (mtDNAcn), an oxidative stress biomarker, are unknown. MATERIALS AND METHODS: Pregnant women were recruited and randomized to one of two cookstove interventions, including a clean-burning liquefied petroleum gas (LPG) stove, or control. Prenatal HAP exposure was determined by serial, personal carbon monoxide (CO) measurements. CBMC mtDNAcn was measured by quantitative polymerase chain reaction. Multivariable linear regression determined associations between prenatal CO and cookstove arm on mtDNAcn. Associations between mtDNAcn and birth outcomes and effect modification by infant sex were explored. RESULTS: LPG users had the lowest CO exposures (p = 0.02 by ANOVA). In boys only, average prenatal CO was inversely associated with mtDNAcn (ß = -14.84, SE = 6.41, p = 0.03, per 1ppm increase in CO). When examined by study arm, LPG cookstove had the opposite effect in all children (LPG ß = 19.34, SE = 9.72, p = 0.049), but especially boys (ß = 30.65, SE = 14.46, p = 0.04), as compared to Control. Increased mtDNAcn was associated with improved birth outcomes. CONCLUSIONS: Increased prenatal HAP exposure reduces CBMC mtDNAcn, suggesting cumulative prenatal oxidative stress injury. An LPG stove intervention may reverse this effect. Boys appear most susceptible.

Neighborhood deprivation and biomarkers of health in Britain: the mediating role of the physical environment.

BACKGROUND: Neighborhood deprivation has been consistently linked to poor individual health outcomes; however, studies exploring the mechanisms involved in this association are scarce. The objective of this study was to investigate whether objective measures of the physical environment mediate the association between neighborhood socioeconomic deprivation and biomarkers of health in Britain. METHODS: We linked individual-level biomarker data from Understanding Society: The UK Household Longitudinal Survey (2010-2012) to neighborhood-level data from different governmental sources. Our outcome variables were forced expiratory volume in 1 s (FEV1%; n=16,347), systolic blood pressure (SBP; n=16,846), body mass index (BMI; n=19,417), and levels of C-reactive protein (CRP; n=11,825). Our measure of neighborhood socioeconomic deprivation was the Carstairs index, and the neighborhood-level mediators were levels of air pollutants (sulphur dioxide [SO2], particulate matter [PM10], nitrogen dioxide [NO2], and carbon monoxide [CO]), green space, and proximity to waste and industrial facilities. We fitted a multilevel mediation model following a multilevel structural equation framework in MPlus v7.4, adjusting for age, gender, and income. RESULTS: Residents of poor neighborhoods and those exposed to higher pollution and less green space had worse health outcomes. However, only SO2 exposure significantly and partially mediated the association between neighborhood socioeconomic deprivation and SBP, BMI, and CRP. CONCLUSION: Reducing air pollution exposure and increasing access to green space may improve population health but may not decrease health inequalities in Britain.

Salud ambiental, vigilancia y monitoreo de la calidad de aire: Contaminante atmosférico: Monóxido de carbono / Environmental health and air quality monitoring: Air pollutant: Carbon monoxide

El monóxido de carbono es un gas tóxico, inodoro e incoloro que se forma por la combustión incompleta de hidrocarburos como gas o kerosene. Las fuentes pueden ser estufas, calefones, braseros, calderas y hornos en malas condiciones de mantenimiento, así como los escapes de automóviles. Las viviendas o escuelas cercanas a calles de alto tránsito pueden estar también expuestas. Es importante señalar que es además uno de los componentes del humo del tabaco. La exposición al monóxido de carbono en el interior de los hogares produce una intoxicación de características graves e incluso con altos niveles de mortalidad. Respecto de la exposición en el aire exterior, las concentraciones más altas normalmente se miden cerca de las vías de transito principales, dado que los vehículos son la principal fuente de CO. se presentan una serie de gráficos que permiten observar los valores de monóxido de carbono registrados en la Ciudad de Buenos Aires. Dichos registros son obtenidos en las tres estaciones de Monitoreo de Calidad del Aire que posee la Ciudad (Estación La Boca, Parque Centenario y Córdoba), las cuales registran las concentraciones de éste contaminante en forma continua (24 horas diarias, los 365 días del año) mediante métodos homologados internacionalmente. (AU)

Ambient air pollution and emergency department visits for asthma: a multi-city assessment of effect modification by age.

Previous studies have found strong associations between asthma morbidity and major ambient air pollutants. Relatively little research has been conducted to assess whether age is a factor conferring susceptibility to air pollution-related asthma morbidity. We investigated the short-term relationships between asthma emergency department (ED) visits and ambient ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and fine particulate matter (PM2.5) in Atlanta (1993-2009), Dallas (2006-2009), and St. Louis (2001-2007). City-specific daily time-series analyses were conducted to estimate associations by age group (0-4, 5-18, 19-39, 40-64, and 65+ years). Sub-analyses were performed stratified by race and sex. City-specific rate ratios (RRs) were combined by inverse-variance weighting to provide an overall association for each strata. The overall RRs differed across age groups, with associations for all pollutants consistently strongest for children aged 5-18 years. The patterns of association across age groups remained generally consistent when models were stratified by sex and race, although the strong observed associations among 5-18 year olds appeared to be partially driven by non-white and male patients. Our findings suggest that age is a susceptibility factor for asthma exacerbations in response to air pollution, with school-age children having the highest susceptibility.

Air pollutants and hospitalization due to pneumonia among children. An ecological time series study.

CONTEXT AND OBJECTIVE: Exposure to air pollutants is one of the factors responsible for hospitalizations due to pneumonia among children. This has considerable financial cost, along with social cost. A study to identify the role of this exposure in relation to hospital admissions due to pneumonia among children up to 10 years of age was conducted. DESIGN AND SETTING: Ecological time series study using data from São José dos Campos, Brazil. METHODS: Daily data on hospitalizations due to pneumonia and on the pollutants CO, O3, PM10 and SO2, temperature and humidity in São José dos Campos, in 2012, were analyzed. A generalized additive model of Poisson's regression was used. Relative risks for hospitalizations due to pneumonia, according to lags of 0-5 days, were estimated. The population-attributable fraction, number of avoidable hospitalizations and cost savings from avoidable hospitalizations were calculated. RESULTS: There were 539 admissions. Exposure to CO and O3 was seen to be associated with hospitalizations, with risks of 1.10 and 1.15 on the third day after exposure to increased CO concentration of 200 ppb and ozone concentration of 20 µg/m3. Exposure to the pollutants of particulate matter and sulfur dioxide were not shown to be associated with hospitalizations. Decreases in CO and ozone concentrations could lead to 49 fewer hospitalizations and cost reductions of R$ 39,000.00. CONCLUSION: Exposure to certain air pollutants produces harmful effects on children's health, even in a medium-sized city. Public policies to reduce emissions of these pollutants need to be implemented.

Air pollutants and hospitalization due to pneumonia among children. An ecological time series study / Poluentes atmosféricos e internações por pneumonia em crianças. Estudo ecológico de série temporal

ABSTRACT CONTEXT AND OBJECTIVE: Exposure to air pollutants is one of the factors responsible for hospitalizations due to pneumonia among children. This has considerable financial cost, along with social cost. A study to identify the role of this exposure in relation to hospital admissions due to pneumonia among children up to 10 years of age was conducted. DESIGN AND SETTING: Ecological time series study using data from São José dos Campos, Brazil. METHODS: Daily data on hospitalizations due to pneumonia and on the pollutants CO, O3, PM10 and SO2, temperature and humidity in São José dos Campos, in 2012, were analyzed. A generalized additive model of Poisson's regression was used. Relative risks for hospitalizations due to pneumonia, according to lags of 0-5 days, were estimated. The population-attributable fraction, number of avoidable hospitalizations and cost savings from avoidable hospitalizations were calculated. RESULTS: There were 539 admissions. Exposure to CO and O3 was seen to be associated with hospitalizations, with risks of 1.10 and 1.15 on the third day after exposure to increased CO concentration of 200 ppb and ozone concentration of 20 µg/m3. Exposure to the pollutants of particulate matter and sulfur dioxide were not shown to be associated with hospitalizations. Decreases in CO and ozone concentrations could lead to 49 fewer hospitalizations and cost reductions of R$ 39,000.00. CONCLUSION: Exposure to certain air pollutants produces harmful effects on children's health, even in a medium-sized city. Public policies to reduce emissions of these pollutants need to be implemented.

RESUMO CONTEXTO E OBJETIVOS: A exposição a poluentes do ar é um dos fatores responsáveis pelas internações por pneumonias em crianças. Esse desfecho tem custo financeiro considerável, além do custo social. Estudo para identificar o papel dessa exposição nas internações em crianças com até 10 anos de idade foi desenvolvido. TIPO DE ESTUDO E LOCAL: Estudo ecológico de séries temporais com dados de São José dos Campos, Brasil. MÉTODOS: Dados diários de internações por pneumonia, dos poluentes CO, O3, PM10, SO2 além de temperatura e umidade de São José dos Campos, em 2012, foram analisados. Utilizou-se modelo aditivo generalizado da regressão de Poisson e foram estimados os riscos relativos para internações por pneumonia segundo defasagens de 0 a 5 dias. Foram calculadas a fração atribuível populacional, as internações evitáveis e a economia nos custos das internações evitáveis. RESULTADOS: Foram 539 internações. Exposição ao CO e O3 se mostraram associadas às internações, com riscos de 1,10 e 1,15 no terceiro dia após a exposição decorrentes de aumento nas concentrações do CO em 200 ppb e nas concentrações de ozônio em 20 µg/m3. Exposições aos poluentes material particulado e dióxido de enxofre não se mostraram associados às internações. Diminuição nas concentrações de CO e O3 poderiam reduzir em 49 internações e de R$ 39 mil nos custos. CONCLUSÃO: Mesmo em uma cidade de médio porte, exposição a determinados poluentes do ar causa efeito danoso à saúde da criança, sendo necessária a implantação de políticas públicas para redução da emissão desses poluentes.

Carbon monoxide pollution and neurodevelopment: A public health concern.

Although an association between air pollution and adverse systemic health effects has been known for years, the effect of pollutants on neurodevelopment has been underappreciated. Recent evidence suggests a possible link between air pollution and neurocognitive impairment and behavioral disorders in children, however, the exact nature of this relationship remains poorly understood. Infants and children are uniquely vulnerable due to the potential for exposure in both the fetal and postnatal environments during critical periods in development. Carbon monoxide (CO), a common component of indoor and outdoor air pollution, can cross the placenta to gain access to the fetal circulation and the developing brain. Thus, CO is of particular interest as a known neurotoxin and a potential public health threat. Here we review overt CO toxicity and the policies regulating CO exposure, detail the evidence suggesting a potential link between CO-associated ambient air pollution, tobacco smoke, and learning and behavioral abnormalities in children, describe the effects of subclinical CO exposure on the brain during development, and provide mechanistic insight into a potential connection between CO exposure and neurodevelopmental outcome. CO can disrupt a number of critical processes in the developing brain, providing a better understanding of how this specific neurotoxin may impair neurodevelopment. However, further investigation is needed to better define the effects of perinatal CO exposure on the immature brain. Current policies regarding CO standards were established based on evidence of cardiovascular risk in adults with pre-existing comorbidities. Thus, recent and emerging data highlighted in this review regarding CO exposure in the fetus and developing child may be important to consider when the standards and guidelines are evaluated and revised in the future.

Carbon monoxide exposures and kitchen concentrations from cookstove-related woodsmoke in San Marcos, Peru.

BACKGROUND: Nearly half of the world's population is exposed to household air pollution (HAP) due to long hours spent in close proximity to biomass-fueled fires. OBJECTIVE: We compare CO exposures and concentrations among study promoted intervention stove users and control stove users in San Marcos Province, Cajamarca region, Peru. METHODS: Passive CO diffusion tubes were deployed over a 48-hour sampling period to measure kitchen CO concentrations and personal mother and child CO exposures in 197 control and 182 intervention households. RESULTS: Geometric means (95% CI) for child, mother, and kitchen measurements were 1.1 (0.9-1.2), 1.4 (1.3-1.6), and 7.3 (6.4-8.3) ppm in control households, and 1.0 (0.9-1.1), 1.4 (1.3-1.6), and 7.3 (6.4-8.2) ppm among intervention households, respectively. CONCLUSION: With no significant differences between control and intervention CO measurements, results suggest that intervention stove maintenance may be necessary for long-term reductions in CO exposures.

Cooking practices, air quality, and the acceptability of advanced cookstoves in Haryana, India: an exploratory study to inform large-scale interventions.

BACKGROUND: In India, approximately 66% of households rely on dung or woody biomass as fuels for cooking. These fuels are burned under inefficient conditions, leading to household air pollution (HAP) and exposure to smoke containing toxic substances. Large-scale intervention efforts need to be informed by careful piloting to address multiple methodological and sociocultural issues. This exploratory study provides preliminary data for such an exercise from Palwal District, Haryana, India. METHODS: Traditional cooking practices were assessed through semi-structured interviews in participating households. Philips and Oorja, two brands of commercially available advanced cookstoves with small blowers to improve combustion, were deployed in these households. Concentrations of particulate matter (PM) with a diameter <2.5 µm (PM2.5) and carbon monoxide (CO) related to traditional stove use were measured using real-time and integrated personal, microenvironmental samplers for optimizing protocols to evaluate exposure reduction. Qualitative data on acceptability of advanced stoves and objective measures of stove usage were also collected. RESULTS: Twenty-eight of the thirty-two participating households had outdoor primary cooking spaces. Twenty households had liquefied petroleum gas (LPG) but preferred traditional stoves as the cost of LPG was higher and because meals cooked on traditional stoves were perceived to taste better. Kitchen area concentrations and kitchen personal concentrations assessed during cooking events were very high, with respective mean PM2.5 concentrations of 468 and 718 µg/m3. Twenty-four hour outdoor concentrations averaged 400 µg/m3. Twenty-four hour personal CO concentrations ranged between 0.82 and 5.27 ppm. The Philips stove was used more often and for more hours than the Oorja. CONCLUSIONS: The high PM and CO concentrations reinforce the need for interventions that reduce HAP exposure in the aforementioned community. Of the two stoves tested, participants expressed satisfaction with the Philips brand as it met the local criteria for usability. Further understanding of how the introduction of an advanced stove influences patterns of household energy use is needed. The preliminary data provided here would be useful for designing feasibility and/or pilot studies aimed at intervention efforts locally and nationally.

Monitoring air pollution: use of early warning systems for public health.

Research confirming the detrimental impact poor ambient air quality and episodes of abnormally high pollutants has on public health, plus differential susceptibility, calls for improved understanding of this complex topic among all walks of society. The public and particularly, vulnerable groups, should be aware of their quality of air, enabling action to be taken in the event of increased pollution. Policy makers must have a sound awareness of current air quality and future trends, to identify issues, guide policies and monitor their effectiveness. These attitudes are dependent upon air pollution monitoring, forecasting and reporting, serving all interested parties. Apart from the underlying national regulatory obligation a country has in reporting air quality information, data output serves several purposes. This review focuses on provision of real-time data and advanced warnings of potentially health-damaging events, in the form of national air quality indices and proactive alert services. Some of the challenges associated with designing these systems include technical issues associated with the complexity of air pollution and its science. These include inability to provide precise exposure concentrations or guidance on long-term/cumulative exposures or effects from pollutant combinations. Other issues relate to the degree to which people are aware and positively respond to these services. Looking to the future, mobile devices such as cellular phones, equipped with sensing applications have potential to provide dynamic, temporally and spatially precise exposure measures for the mass population. The ultimate aim should be to empower people to modify behaviour-for example, when to increase medication, the route/mode of transport taken to school or work or the appropriate time to pursue outdoor activities-in a way that protects their health as well as the quality of the air they breathe.

A mathematical modeling approach to risk assessment for normal and anemic women chronically exposed to carbon monoxide from biomass-fueled cookstoves.

In developing countries, the chronic exposure to carbon monoxide (CO) from biomass-fueled cookstoves may pose a significant health risk for women who use these stoves, especially for those with underlying clinical conditions that impair tissue oxygenation, e.g., anemia and coronary artery disease. CO concentrations measured in the vicinity of these cookstoves often exceed World Health Organization (WHO) indoor air guidelines for an 8-h average (9 ppm) and a 1-h maximum (26 ppm). Carboxyhemoglobin levels, reported infrequently because they are difficult to obtain, often exceed the WHO threshold of 2.5%. Despite this evidence, specific adverse effects have not yet been linked with chronic CO exposures in these women. Furthermore, anemia, which is prevalent in populations that use biomass fuels, could exacerbate the adverse effects of chronic CO exposure. Because of the difficulties inherent in conducting prospective studies to address this issue, we used a mathematical model to calculate the effects of reported CO levels and exercise on carboxyhemoglobin for women living in 1) Guatemalan villages at altitudes of 4,429-4,593 ft, and 2) coastal villages in Pakistan. In addition, we used the model to calculate the effects of CO exposures in women with moderate to severe anemia on specific physiological parameters (carboxyhemoglobin, carboxymyoglobin, cardiac output, and tissue Po(2)) at exercise levels representing the activities in which these women would be engaged. Our results demonstrate the efficacy of using a mathematical model to predict the physiologic responses to CO and also demonstrate that chronic anemia is a critically important determinant of CO toxicity in these women.

[Screening for carbon monoxide (CO) poisoning by general practitioners in home visits]. / Dépistage des intoxications au monoxyde de carbone (CO) par des médecins généralistes effectuant des visites à domicile.

OBJECTIVE: To evaluate the interest of carbon monoxide (CO) detector used by general practionners visiting patients at home. METHODS: CO detector (cost: 200 euros) was attributed to 300 general practionners visiting at least 20 patients at home per week. Alarm was triggered when ambient CO concentration exceeded 80ppm. Measurement of CO in expired breath was also possible. Activity and alarms were prospectively collected. Circumstances of intoxication were recorded. Evaluation was finally performed. The end-poind was to quantify CO-poisoning detected by the use of the device and the cost of this stratégy. RESULTS: From November 2001 to November 2004, 65 scenes of intoxication with 79 victims were prospectively reported by 12 general practionners. Final evaluation revealed that 23 physicians omitted to declare alarms. Alarm incidence was of 1 for 17.527 visits; with a related cost of approximately 858 euros for 24 months. Ambient carbon monoxide concentration exceeded 200ppm in 25% of cases. Hospital admission was required for 91% of the victims. Hyperbaric oxygen therapy was performed in two cases. General practionners (n=272) considered that CO detector was useful for safety reasons (91%), they wanted to continue the experience, but did not plan to buy such device (59%). DISCUSSION: Use of CO detectors by general practionners visiting patients at home allowed to identify 65 scenes of CO intoxication. In most cases, the cause of the visit did not suggested CO poisoning. The cost of the device seems to limits its large use. CONCLUSION: CO detector is a safety tool for both general prationners and patients. Its large use has to be questioned.

Emergency hospital admissions for cardiovascular diseases and ambient levels of carbon monoxide: results for 126 United States urban counties, 1999-2005.

BACKGROUND: Evidence on risk of cardiovascular disease (CVD) hospitalization associated with short-term exposure to outdoor carbon monoxide (CO), an air pollutant primarily generated by traffic, is inconsistent across studies. Uncertainties remain on the degree to which associations are attributable to other traffic pollutants and whether effects persist at low levels. METHODS AND RESULTS: We conducted a multisite time-series study to estimate risk of CVD hospitalization associated with short-term CO exposure in 126 US urban counties during 1999-2005 for >9.3 million Medicare enrollees aged > or =65 years. We considered models with adjustment by other traffic-related pollutants: NO2, fine particulate matter (with aerodynamic diameter < or =2.5 microm), and elemental carbon. We found a positive and statistically significant association between same-day CO and increased risk of hospitalization for multiple CVD outcomes (ischemic heart disease, heart rhythm disturbances, heart failure, cerebrovascular disease, total CVD). The association remained positive and statistically significant but was attenuated with copollutant adjustment, especially NO2. A 1-ppm increase in same-day daily 1-hour maximum CO was associated with a 0.96% (95% posterior interval, 0.79%, 1.12%) increase in risk of CVD admissions. With same-day NO(2) adjustment, this estimate was 0.55% (0.36%, 0.74%). The risk persisted at low CO levels <1 ppm. CONCLUSIONS: We found evidence of an association between short-term exposure to ambient CO and risk of CVD hospitalizations, even at levels well below current US health-based regulatory standards. This evidence indicates that exposure to current CO levels may still pose a public health threat, particularly for persons with CVD.

[Assessment of in vitro immune response in a young population exposed to atmospheric contamination of Guadalajara]. / Evaluación de la respuesta inmunológica in vitro en una población joven expuesta a la contaminación atmosférica de Guadalajara.

BACKGROUND: Atmospheric pollutants may cause alterations on health of persons exposed to urban environment. OBJECTIVE: To evaluate in vitro immunological response in young population exposed to different levels of atmospheric pollution. PARTICIPANTS AND METHODS: The study was performed in two groups of young men, one from Guadalajara, and the other from Tlajomulco. The volunteers had to be healthy and without precedents of atopia. The immunological responses studied on PBMC were: stimulation index by timidin incorporation, CD25 expression by flow citometry, and production of citokines IL-2 and IL-4 by ELISAtest. Atmospheric parameters monitored were: NO2, O3, SO2, CO and PM10. RESULTS: In Guadalajara the concentrations of NO2 and PM10 exceeded in 30% and 40%, respectively, the index established by WHO. Stimulation index of PBMC of the young men to Guadalajara was 18 +/- 4, whereas that of the volunteers from Tlajomulco was 23 +/- 3. Expression of CD25 did not show a significant difference between studied groups. IL-2 and IL-4 levels were similar between the young men of the city and those from the rural area. CONCLUSION: The environmental pollution in Guadalajara did not modify in a significant way proliferation, CD25 expression, nor secretion of IL-2 and IL-4 on PBMC. This demonstrates that healthy young men are less susceptible than other groups to the alterations caused by exposure to moderate levels of atmospheric pollutants.

Air pollution in Athens basin and health risk assessment.

An inventory of air pollution sources within the Athens basin is carried out for the years 1989, 1992 and 1998 and the results are inputted in a climatological model for predicting ambient concentrations. Despite of the significant growth in the number of road vehicles and the deteriorating traffic, the emissions and ambient concentrations of fine particulates, CO, NOx and VOC appear to remain reasonably constant over for the period 1989 to 1998, while these of SO2 and Pb are reduced, mainly due to the renewal of vehicle fleet, the use of catalytic technologies and the improved quality of the used fuel. The results further indicate that for CO, NOx and VOC the major source is road traffic, while for PM2.5 and SO2 both space heating and traffic share responsibility. The air pollutant concentrations monitored by the network of 11 stations are reviewed and statistics related to air quality guidelines are presented. As fine particulate levels are not monitored, approximate PM2.5 and PM10 concentrations are derived from black smoke ones on basis of experimentally determined conversion factors. The computed and monitored air pollution levels are compared and found in reasonable agreement. The results of the above analysis show that the levels of all 'classical' pollutants, with the exception of SO2 and Pb, exceed significantly the WHO guidelines and are thus expected to exert a significant health impact. The latter could be quantified in relation to the PM2.5 or PM10 levels on the basis of risk assessment information developed by the World Health Organization (WHO). The results show that the existing levels of fine particle concentrations in Athens increase significantly the mortality and morbidity, and reduce the average longevity of the entire population from 1.3 to 1.7 years.

Use of an index to reflect the aggregate burden of long-term exposure to criteria air pollutants in the United States.

Air pollution control in the United States for five common pollutants--particulate matter, ground-level ozone, sulfur dioxide, nitrogen dioxide, and carbon monoxide--is based partly on the attainment of ambient air quality standards that represent a level of air pollution regarded as safe. Regulatory and health agencies often focus on whether standards for short periods are attained; the number of days that standards are exceeded is used to track progress. Efforts to explain air pollution to the public often incorporate an air quality index that represents daily concentrations of pollutants. While effects of short-term exposures have been emphasized, research shows that long-term exposures to lower concentrations of air pollutants can also result in adverse health effects. We developed an aggregate index that represents long-term exposure to these pollutants, using 1995 monitoring data for metropolitan areas obtained from the U.S. Environmental Protection Agency's Aerometric Information Retrieval System. We compared the ranking of metropolitan areas under the proposed aggregate index with the ranking of areas by the number of days that short-term standards were exceeded. The geographic areas with the highest burden of long-term exposures are not, in all cases, the same as those with the most days that exceeded a short-term standard. We believe that an aggregate index of long-term air pollution offers an informative addition to the principal approaches currently used to describe air pollution exposures; further work on an aggregate index representing long-term exposure to air pollutants is warranted.