Particulate air pollution and respiratory disease in Anchorage, Alaska

Particulate Matter Emission Factors for Dairy Facilities and Cattle Feedlots during Summertime in Texas

Particulate matter (PM) emissions from dairies and feedlot sources require regular emission factor update. Likewise, development of simple measurement technique to accurately measure pollution concentration is warranted to limit the impact of air pollution and take necessary actions. During June of 2020, a dairy facility from central Texas and a feedlot from the Texas Panhandle region, titled as Dairy B and Feedlot C, respectively, were chosen for measurement of PM emissions in the state of Texas to represent dairy facilities and cattle feedlots PM emission rates. Four stations, each assigned with an EPA-approved Federal Reference Method (FRM) sampler, Texas A&M University (TAMU) designed sampler and handheld non-FRM AEROCET (MET One Instruments) sampler for collocation, were selected within each sampling locations. Drones were also utilized mounted with a handheld AEROCET sampler for simultaneously sampling at a certain height. PM_2.5 emissions of Dairy B were all below 24-h PM_2.5 standard of 35 μg m^-3 as specified by National Ambient Air Quality Standards (NAAQS) even at the 98th percentile. The PM ratio between regulated PM₁₀ to PM_2.5 was determined to make an estimate of relative percentage of coarser particles to fine particles in both feedlot and the dairy representative animal facilities. The maximum mean emission factor determined using AERMOD for PM_2.5 and PM₁₀ was found to be 0.53 and 7.09 kg 1000-hd^-1 d^-1, respectively, for the dairy facility while 8.93 and 33.42 kg 1000-hd^-1 d^-1, respectively, for the feedlot. A conversion factor and correlation matrix were developed in this study to relate non-FRM sampler data from the handheld AERCET samplers with FRM samplers. Cheaper handheld samplers (AEROCETs) may play a potential role in quick and relatively instant measurement of PM emissions to initiate necessary preventive actions to control PM emission from dairy facility and feedlot sources.

Air Pollution and Respiratory Hospital Admissions in Kuwait: The Epidemiological Applicability of Predicted PM2.5 in Arid Regions

Dust is a major component of fine particulate matter (PM_2.5) in arid regions; therefore, concentrations of this pollutant in countries such as Kuwait exceed air quality standards. There is limited understanding on the impact and burden of high PM_2.5 concentrations on morbidity in these countries. In this study, we explore the association of PM_2.5 and the risk of respiratory hospital admissions in Kuwait. A time-series regression model was used to investigate daily variations in respiratory admissions and PM_2.5 concentrations from 2010 to 2018. Due to the lack of historical air quality sampling in Kuwait, we used estimated daily PM_2.5 levels from a hybrid PM_2.5 prediction model. Individual and cumulative lag effects of PM_2.5 over a 5-day period were estimated using distributed lag linear models. Associations were stratified by sex, age, and nationality. There were 218,749 total respiratory admissions in Kuwait during the study period. Results indicate that for every 10 μg/m³ increase in PM_2.5, a 1.61% (95% CI = 0.87, 2.35%) increase in respiratory admissions followed over a 5-day cumulative lag. Our estimates show that a 10 μg/m³ reduction in average exposure will potentially avert 391 yearly respiratory admissions (95% CI = 211,571), with 265 fewer admissions among Kuwaitis (95% CI = 139,393) and 262 fewer admissions among children under 15 years of age (95% CI = 125,351). Different strata of the Kuwaiti population are vulnerable to respiratory hospitalization with short-term exposure to PM_2.5, especially those under 15 years of age. The findings are informative for public health authorities in Kuwait and other dust-prone countries.

Cold Climate Impact on Air-Pollution-Related Health Outcomes: A Scoping Review

In cold temperatures, vehicles idle more, have high cold-start emissions including greenhouse gases, and have less effective exhaust filtration systems, which can cause up to ten-fold more harmful vehicular emissions. Only a few vehicle technologies have been tested for emissions below -7 °C (20 °F). Four-hundred-million people living in cities with sub-zero temperatures may be impacted. We conducted a scoping review to identify the existing knowledge about air-pollution-related health outcomes in a cold climate, and pinpoint any research gaps. Of 1019 papers identified, 76 were selected for review. The papers described short-term health impacts associated with air pollutants. However, most papers removed the possible direct effect of temperature on pollution and health by adjusting for temperature. Only eight papers formally explored the modifying effect of temperatures. Five studies identified how extreme cold and warm temperatures aggravated mortality/morbidity associated with ozone, particles, and carbon-monoxide. The other three found no health associations with tested pollutants and temperature. Additionally, in most papers, emissions could not be attributed solely to traffic. In conclusion, evidence on the relationship between cold temperatures, traffic-related pollution, and related health outcomes is lacking. Therefore, targeted research is required to guide vehicle regulations, assess extreme weather-related risks in the context of climate change, and inform public health interventions.

An association between PM2.5 and pediatric respiratory outpatient visits in four Chinese cities

BACKGROUND

The effects of exposure to particulate matter with aerodynamic diameter less than 2.5 μm (PM_2.5) on children's respiratory system were investigated in numerous epidemiological literatures. However, studies on the association between PM_2.5 and pediatric outpatient visits for respiratory diseases, especially considering the multicenter studies were limited in China.

OBJECTIVES

To study the association between the short-term exposure to PM_2.5 and the number of children's outpatient visits for respiratory diseases in four Chinese cities as well as the pooled health effects.

METHODS

Data of pediatric outpatient visits for respiratory diseases (RD, ICD: J00-J99) from representative hospitals in Shijiazhuang (SJZ), Xi'an (XA), Nanjing (NJ) and Guangzhou (GZ) in China from 2015 to 2018 were collected and the air quality data for the same period were collected from environmental protection departments. Generalized additive model (GAM) with quasi-Poisson regression was conducted to analyze the effects of PM_2.5 on the number of pediatric outpatient visits in each city. Single-day lag model (lag0 to lag7) and moving average lag model (lag01 and lag07) were used to examine the lag effects and cumulative effects. Random-effects meta-analysis was used to pool the estimated risks of four cities. The interactions between PM_2.5 and temperature were also explored.

RESULTS

The average daily/total outpatient visits for RD, in SJZ, XA, NJ and GZ from 2015 to 2018 were 854.2/1,245,384, 2353.9/3,439,025, 1267.2/1,851,438 and 1399.5/2,044,740 respectively. The percentages of acute upper respiratory infections (URD, ICD: J00-J06) and other acute lower respiratory infections (LRD, ICD: J20-J22) in RD were 33%, 13% (SJZ), 43%, 32% (XA), 26%, 21% (NJ) and 54%, 26% (GZ). The largest pooled estimates of single-day lag effects for RD, URD, and LRD were at lag0, lag0 and lag1. Every 10 μg/m³ increase in PM_2.5 concentration was associated with a 0.46% (95%CI: 0.21%-0.70%), 0.50% (95%CI: 0.19%-0.81%) and 0.42% (95%CI: 0.06%-0.79%) increased number of outpatient visits significantly. While max cumulative effects which were all at lag 07 were 1.10% (95%CI: 0.46%-1.74%), 0.96% (95%CI: 0.20%-1.73%) and 1.06% (95%CI: 0.12%-2.00%). Less polluted cities (GZ and NJ) showed greater city-specific excess risks, but the excess risks significantly decreased after adjusting for NO₂ in two-pollutant models. Generally, PM_2.5 showed larger health hazards on lower temperature days.

CONCLUSIONS

Our study showed that exposure to the ambient PM_2.5 was associated with the increase of the number of outpatient visits with pediatric respiratory diseases in four Chinese cities. The health effects of PM_2.5 may not be independent of other air pollutants and could be modified by temperature.

New normal baseline data during nationwide lock down due to Covid 19 pandemic in the world's largest ship recycling yard at Alang, India

A detailed study to generate the new normal baseline data has been carried out during nationwide lockdown (May 12 to May 16, 2020) covering sampling for ambient air, coastal water, coastal sediments, fish and bioaccumulation of heavy metals, in an around Alang, the world's biggest ship recycling yard. The lockdown data were compared with 2018 and 2019 observed data. PM10 values during lockdown were reduced by 3.75 to 4.5 times as compared with previous 2 years. Similarly, four-fold reduction of PM2.5 and SPM values was observed during lockdown. The gaseous pollutants like NO2 and O3 are within safe limit. Overall air quality index (AQI) improved significantly during lockdown. Similarly, there was drastic reduction in the majority of the nutrient parameters in the coastal water. Different heavy metal concentration in the coastal sediments samples also showed strong reduction during lockdown sampling in comparison with other two sampling. This proves that the coastal environment has its efficient self-cleaning potentials if there is considerable reduction in the anthropogenic as well as industrial activities. Diversity of phytoplankton and zooplankton also increased. The results were validated using statistical techniques like analysis of variance and least significance difference (LSD).

Health Impact Assessment of Volcanic Ash Inhalation: A Comparison With Outdoor Air Pollution Methods

This paper critically appraises the extrapolation of concentration-response functions (CRFs) for fine and coarse particulate matter, PM2.5 and PM10, respectively, used in outdoor air pollution health impact assessment (HIA) studies to assess the extent of health impacts in communities exposed to volcanic emissions. Treating volcanic ash as PM, we (1) consider existing models for HIA for general outdoor PM, (2) identify documented health effects from exposure to ash in volcanic eruptions, (3) discuss potential issues of applying CRFs based on the composition and concentration of ash-related PM, and (4) critically review available case studies of volcanic exposure scenarios utilizing HIA for outdoor air pollution. We identify a number of small-scale studies focusing on populations exposed to volcanic ash; exposure is rarely quantified, and there is limited evidence concerning the health effects of PM from volcanic eruptions. That limited evidence is, however, consistent with the CRFs typically used for outdoor air pollution HIA. Two health assessments of exposure to volcanic emissions have been published using population- and occupational-based CRFs, though each application entails distinct assumptions and limitations. We conclude that the best available strategy, at present, is to apply outdoor air pollution risk estimates to scenarios involving volcanic ash emissions for the purposes of HIA. However, due to the knowledge gaps on, for example, the health effects from exposure to volcanic ash and differences in ash composition, there is inherent uncertainty in this application. To conclude, we suggest actions to enable better prediction and assessment of health impacts of volcanic emissions.

The nexus between climate change, ecosystem services and human health: Towards a conceptual framework

This paper addresses the impact that changes in natural ecosystems can have on health and wellbeing focusing on the potential co-benefits that green spaces could provide when introduced as climate change adaptation measures. Ignoring such benefits could lead to sub-optimal planning and decision-making. A conceptual framework, building on the ecosystem-enriched Driver, Pressure, State, Exposure, Effect, Action model (eDPSEEA), is presented to aid in clarifying the relational structure between green spaces and human health, taking climate change as the key driver. The study has the double intention of (i) summarising the literature with a special emphasis on the ecosystem and health perspectives, as well as the main theories behind these impacts, and (ii) modelling these findings into a framework that allows for multidisciplinary approaches to the underlying relations between human health and green spaces. The paper shows that while the literature based on the ecosystem perspective presents a well-documented association between climate, health and green spaces, the literature using a health-based perspective presents mixed evidence in some cases. The role of contextual factors and the exposure mechanism are rarely addressed. The proposed framework could serve as a multidisciplinary knowledge platform for multi-perspecitve analysis and discussion among experts and stakeholders, as well as to support the operationalization of quantitative assessment and modelling exercises.

Health Services Utilization in Asthma Exacerbations and PM10 Levels in Rural Colorado

RATIONALE

The San Luis Valley in rural Colorado often has elevated levels of ambient particulate matter. To date little is known about the impact of ambient particulate matter levels and medical care utilization due to asthma exacerbation in rural communities.

OBJECTIVES

We investigated the impact of ambient particulate matter concentrations on emergency/urgent visits and hospitalizations for asthma in a rural community.

METHODS

Daily ambient particulate matter concentrations from an air quality monitor in the San Luis Valley (2003-2012) were obtained from the state health department. Deidentified data for emergency/urgent visits with a diagnosis code for asthma were collected from the local health care system organization. A generalized linear model using splines and employing generalized estimating equations for correlated measures over time was used to examine the association between daily counts of emergency/urgent visits for asthma and 3- to 5-day averaged ambient particulate matter concentrations.

RESULTS

For each 15-μg/m3 increase in 3-day averaged ambient particulate matter, there was an associated 3.1% increase in hospital counts for all patients with asthma (95% confidence interval, 0.3-5.9%; P = 0.03). When the 3-day average exceeded 50 μg/m3, asthma hospital visits increased by 16.8% (P = 0.03), and when it exceeded 100 μg/m3, visits increased by 65.8% (P = 0.002). In children, the odds of one asthma event requiring an emergency/urgent care visit increased 5.0% with each 15-μg/m3 increase in 3-day averaged ambient particulate matter (P = 0.22).

CONCLUSIONS

We observed associations between ambient air levels of particulate matter with a diameter less than 10 μm and emergency/urgent care visits and hospitalization counts in a rural U.S. community prone to dust storms and Environmental Protection Agency exceedances.

The Impact of Indonesian Forest Fires on Singaporean Pollution and Health

Between 1990 and 2015, Indonesia lost nearly 25 percent of its forests, largely due to intentional burning to clear land for cultivation of palm oil and timber plantations.1 The neighboring "victim countries" experienced severe deteriorations in air quality as a result of these fires. For example, Singapore experienced record air pollution levels in June of 2013 and again in September of 2015 as a result of the Indonesian forest fires.2 This air pollution is associated with increased incidences of upper respiratory tract infections, acute conjunctivitis, lung disease, asthma, bronchitis, emphysema, and pneumonia, among other ailments.2 Quantifying the impact of air pollution on health outcomes is challenging because pollution levels are often nonrandom for a variety of reasons, including policy endogeneity and sorting (Dominici, Greenstone, and Sunstein 2014). In this paper we offer the first causal analysis of the transboundary health effects of the Indonesian forest burning. The Indonesian fires induce exogenous variation in Singaporean air quality. We take advantage of this by using satellite fire data to instrument for changes in Singaporean air quality. Since Singapore is only 277.6 square miles in area (two-thirds the size of New York City), air pollution resulting from the fires is homogeneously spread so that sorting is less likely to be an issue. Using a two-stage least squares approach, we find that from 2010 through mid-2016, the Indonesian fires caused a statistically significant increase in pollution levels in Singapore. Our study also provides evidence that polyclinic attendances for acute respiratory tract infections and acute conjunctivitis in Singapore increased as a result of the deterioration in air quality. The reduced form estimates show that a one standard deviation increase in our measure of fires causes a 0.7 standard deviation increase in polyclinic attendances for each of these illnesses. These findings provide causal evidence of the transboundary pollution and health impacts of the Indonesian forest burning on neighboring Singapore.

Long-term health effects of the Eyjafjallajökull volcanic eruption: a prospective cohort study in 2010 and 2013

OBJECTIVES

To examine the long-term development of physical and mental health following exposure to a volcanic eruption.

DESIGN

Population-based prospective cohort study.

SETTING

In spring 2010, the Icelandic volcano Eyjafjallajökull erupted. Data were collected at 2 time points: in 2010 and 2013.

PARTICIPANTS

Adult residents in areas close to the Eyjafjallajökull volcano (N=1096), divided according to exposure levels, and a non-exposed sample (n=475), with 80% participation rate in 2013.

MAIN OUTCOME MEASURES

Physical symptoms in the previous year (chronic) and previous month (recent), and psychological distress (General Health Questionnaire-12-item version, GHQ-12), perceived stress (Perceived Stress Scale, PSS-4) and post traumatic stress disorder (PTSD) symptoms (Primary Care PTSD, PC-PTSD).

RESULTS

In the exposed group, certain symptoms were higher in 2013 than in 2010, for example, morning phlegm during winter (OR 2.14; 95% CI 1.49 to 3.06), skin rash/eczema (OR 2.86; 95% CI 1.76 to 4.65), back pain (OR 1.45; 95% CI 1.03 to 2.05) and insomnia (OR 1.53; 95% CI 1.01 to 2.30), in addition to a higher prevalence of regular use of certain medications (eg, for asthma (OR 2.80; 95% CI 1.01 to 7.77)). PTSD symptoms decreased between 2010 and 2013 (OR 0.33; 95% CI 0.17 to 0.61), while the prevalence of psychological distress and perceived stress remained similar. In 2013, the exposed group showed a higher prevalence of various respiratory symptoms than did the non-exposed group, such as wheezing without a cold (high exposure OR 2.35; 95% CI 1.27 to 4.47) and phlegm (high exposure OR 2.81; 95% CI 1.48 to 5.55), some symptoms reflecting the degree of exposure (eg, nocturnal chest tightness (medium exposed OR 3.09; 95% CI 1.21 to 10.46; high exposed OR 3.42; 95% CI 1.30 to 11.79)).

CONCLUSIONS

The findings indicate that people exposed to a volcanic eruption, especially those most exposed, exhibit increased risk of certain symptoms 3-4 years after the eruption.

Particulate Matter in Second-Hand Smoke Emitted from Different Cigarette Sizes and Types of the Brand Vogue Mainly Smoked by Women

Indoor air pollution with harmful particulate matter (PM) is mainly caused by cigarette smoke. Super-Slim-Size-Cigarettes (SSL) are considered a less harmful alternative to King-Size-Cigarettes (KSC) due to longer filters and relatively low contents. We ask if “Combined Mainstream and Sidestream Smoke” (CMSS)-associated PM levels of SSL are lower than of KSC and thus are potentially less harmful. PM concentrations in CMSS (PM₁₀, PM_2.5, and PM₁) are measured from four cigarette types of the brand Vogue, using an “automatic-environmental-tobacco-smoke-emitter” (AETSE) and laser aerosol spectrometry: SSL-BLEUE, -MENTHE, -LILAS and KSC-La Cigarette and -3R4F reference. This analysis shows that SSL MENTHE emitted the highest amount of PM, and KSC-La Cigarette the lowest. 3R4F reference emitted PM in the middle range, exceeding SSL BLEUE and falling slightly below SSL LILAS. It emerged that PM₁ constituted the biggest proportion of PM emission. The outcome shows significant type-specific differences for emitted PM concentrations. Our results indicate that SSL are potentially more harmful for passive smokers than the respective KSC. However, this study cannot give precise statements about the general influence of the size of a cigarette on PM. Alarming is that PM₁ is responsible for the biggest proportion of PM pollution, since smaller particles cause more harmful effects.

Particulate matter properties and health effects: consistency of epidemiological and toxicological studies

Identifying the ambient particulate matter (PM) fractions or constituents, critically involved in eliciting adverse health effects, is crucial to the implementation of more cost-efficient abatement strategies to improve air quality. This review focuses on the importance of different particle properties for PM-induced effects, and whether there is consistency in the results from epidemiological and experimental studies. An evident problem for such comparisons is that epidemiological and experimental data on the effects of specific components of ambient PM are limited. Despite this, some conclusions can be drawn. With respect to the importance of the PM size-fractions, experimental and epidemiological studies are somewhat conflicting, but there seems to be a certain consistency in that the coarse fraction (PM10-2.5) has an effect that should not be neglected. Better exposure characterization may improve the consistency between the results from experimental and epidemiological studies, in particular for ultrafine particles. Experimental data indicate that surface area is an important metric, but composition may play an even greater role in eliciting effects. The consistency between epidemiological and experimental findings for specific PM-components appears most convincing for metals, which seem to be important for the development of both pulmonary and cardiovascular disease. Metals may also be involved in PM-induced allergic sensitization, but the epidemiological evidence for this is scarce. Soluble organic compounds appear to be implicated in PM-induced allergy and cancer, but the data from epidemiological studies are insufficient for any conclusions. The present review suggests that there may be a need for improvements in research designs. In particular, there is a need for better exposure assessments in epidemiological investigations, whereas experimental data would benefit from an improved comparability of studies. Combined experimental and epidemiological investigations may also help answer some of the unresolved issues.

Comparison of how ambient PMc and PM2.5 influence the inflammatory potential

Airborne particulate matter (PM) is one of the six criteria air pollutants currently regulated by the U.S. Environmental Protection Agency (EPA), with existing ambient standards for PM2.5 and PM10. Currently there are no health-based regulations for the size fraction between 2.5 and 10 µm, commonly known as the coarse fraction (PMc). The present study investigates current gaps in knowledge for PMc including exposure toxicity and PM ratios (PMc:PM2.5) in PM10. Throughout the world, all the three PM size fractions have been shown to be associated with adverse impacts. Recent studies have shown that PMc can be more detrimental to susceptible populations when directly compared to PM2.5, and that the PMc fraction in PM10 can account for the majority of the inflammatory response from PM10 exposure. In our studies we utilized a bone marrow-derived mouse macrophage in vitro system to compare the inflammatory potential of PMc, PM2.5 and mixtures of the two. The result was a linear increase in interleukin(IL) -1β with increasing levels of exposure to winter and summer PMc, as compared to PM2.5, which exhibited logarithmic growth. Also, exposure to PM10 as a function of PM2.5 and PMc mass ratios showed that IL-1β and TNF-α levels increased synergistically with a greater burden of PMc. Endotoxin content in the PM did not correlate with these results, suggesting that other activators in PMc are likely responsible for activating the NF-κB pathway and the inflammasome.

Predicting primary PM2.5 and PM0.1 trace composition for epidemiological studies in California

The University of California-Davis_Primary (UCD_P) chemical transport model was developed and applied to compute the primary airborne particulate matter (PM) trace chemical concentrations from ∼ 900 sources in California through a simulation of atmospheric emissions, transport, dry deposition and wet deposition for a 7-year period (2000-2006) with results saved at daily time resolution. A comprehensive comparison between monthly average model results and available measurements yielded Pearson correlation coefficients (R) ≥ 0.8 at ≥ 5 sites (out of a total of eight) for elemental carbon (EC) and nine trace elements: potassium, chromium, zinc, iron, titanium, arsenic, calcium, manganese, and strontium in the PM2.5 size fraction. Longer averaging time increased the overall R for PM2.5 EC from 0.89 (1 day) to 0.94 (1 month), and increased the number of species with strong correlations at individual sites. Predicted PM0.1 mass and PM0.1 EC exhibited excellent agreement with measurements (R = 0.92 and 0.94, respectively). The additional temporal and spatial information in the UCD_P model predictions produced population exposure estimates for PM2.5 and PM0.1 that differed from traditional exposure estimates based on information at monitoring locations in California Metropolitan Statistical Areas, with a maximum divergence of 58% at Bakersfield. The UCD_P model has the potential to improve exposure estimates in epidemiology studies of PM trace chemical components and health.

Short-term effects of the particulate pollutants contained in Saharan dust on the visits of children to the emergency department due to asthmatic conditions in Guadeloupe (French Archipelago of the Caribbean)

Background

The prevalence of asthma in children is a significant phenomenon in the Caribbean. Among the etiologic factors aggravating asthma in children, environmental pollution is one of the main causes. In Guadeloupe, pollution is primarily transported by Saharan dust including inhalable particles.

Methods

This study assesses, over one year (2011), the short-term effects of pollutants referred to as PM₁₀ (PM₁₀: particulate matter <10 µm) and PM_2.5–10 (PM_2.5–10: particulate matter >2.5 µm and <10 µm) contained in Saharan dust, on the visits of children aged between 5 and 15 years for asthma in the health emergency department of the main medical facility of the archipelago of Guadeloupe. A time-stratified case-crossover model was applied and the data were analysed by a conditional logistic regression for all of the children but also for sub-groups corresponding to different age classes and genders.

Results

The visits for asthma concerned 836 children including 514 boys and 322 girls. The Saharan dust has affected 15% of the days of the study (337 days) and involved an increase in the average daily concentrations of PM₁₀ (49.7 µg/m³ vs. 19.2 µg/m³) and PM _2.5–10 (36.2 µg/m³ vs. 10.3 µg/m³) compared to days without dust. The excess risk percentages (IR%) for visits related to asthma in children aged between 5 and 15 years on days with dust compared to days without dust were, for PM_{10, (}(IR %: 9.1% (CI95%, 7.1%–11.1%) versus 1.1%(CI95%, −5.9%–4.6%)) and for PM_2.5–10 (IR%: 4.5%(CI95%, 2.5%–6.5%) versus 1.6% (CI95%, −1.1%–3.4%). There was no statistical difference in the IR% for periods with Saharan dust among different age group of children and between boys and girls for PM₁₀ and PM_2.5–10.

Conclusion

The PM₁₀ and PM_2.5–10 pollutants contained in the Saharan dust increased the risk of visiting the health emergency department for children with asthma in Guadeloupe during the study period.

A retrospective study on acute health effects due to volcanic ash exposure during the eruption of Mount Etna (Sicily) in 2002

Background

Mount Etna, located in the eastern part of Sicily (Italy), is the highest and most active volcano in Europe. During the sustained eruption that occurred in October-November 2002 huge amounts of volcanic ash fell on a densely populated area south-east of Mount Etna in Catania province. The volcanic ash fall caused extensive damage to infrastructure utilities and distress in the exposed population. This retrospective study evaluates whether or not there was an association between ash fall and acute health effects in exposed local communities.

Methods

We collected the number and type of visits to the emergency department (ED) for diseases that could be related to volcanic ash exposure in public hospitals of the Province of Catania between October 20 and November 7, 2002. We compared the magnitude of differences in ED visits between the ash exposure period in 2002 and the same period of the previous year 2001.

Results

We observed a significant increase of ED visits for acute respiratory and cardiovascular diseases, and ocular disturbances during the ash exposure time period.

Conclusions

There was a positive association between exposure to volcanic ash from the 2002 eruption of Mount Etna and acute health effects in the Catania residents. This study documents the need for public health preparedness and response initiatives to protect nearby populations from exposure to ash fall from future eruptions of Mount Etna.

Air quality influences the prevalence of hay fever and sinusitis

OBJECTIVES

Determine associations between air quality and the prevalence of hay fever and sinusitis.

STUDY DESIGN

Cross-sectional study.

METHODS

The National Health Interview Survey for the calendar years 1997-2006 adult sample was analyzed to determine for each calendar year the one-year period prevalence of the two respiratory conditions, hay fever and sinusitis and the nonrespiratory (control) condition, weak/failing kidneys. From the Environmental Protection Agency, yearly historical data for air quality criteria pollutants, carbon monoxide, nitrous dioxide, sulfur dioxide, and particulate matter, were tabulated. Graphical and linear regression analyses were conducted for each disease condition against each of the air quality variables to determine if higher pollutant concentrations predicted a higher prevalence for the disease condition.

RESULTS

A total of 313,982 patients were studied over the 10 calendar years 1997-2006. Mean patient age increased very slightly from year to year (overall average, 45.2 years); the percentage of female patients remained the same. The air concentrations of each of the criteria pollutants decreased steadily over time with the exception of particular matter, which reached a plateau in the most recent 3 years. For each of the disease conditions a statistically significant relationship with air quality (all p < .001) was obtained. For the control condition of kidney failure/weakening, the standardized regression coefficient with air quality was very small (range-0.001-0.004). For hay fever and sinusitis, substantially larger coefficients were obtained ranging from 0.0120-.016 and 0.013-0.027, respectively.

CONCLUSIONS

Prevalence of hay fever and sinusitis are correlated with air quality. Improvements in air quality are associated with decreased prevalence of both hay fever and sinusitis. Laryngoscope, 2009.

The Effect of Coarse Ambient Particulate Matter on First, Second, and Overall Hospital Admissions for Respiratory Disease Among the Elderly

The objective of this article is to examine differences in the effect of ambient particulate matter on first, second, and overall hospital admissions for respiratory disease among the elderly. We studied 8989 adults 65 yr of age or older living in the greater Vancouver area who were admitted to hospital for any acute respiratory disease (ICD-9 codes 460-519) between June 1, 1995, and March 31, 1999. Time-series analysis was used to evaluate the association between respiratory admissions and daily measures of particulate matter (PM10, PM2.5, and PM10 - 2.5) in urban air, after adjustment for gaseous copollutants (CO, O3, NO2, and SO2) and meteorological variables. Repeated admissions for respiratory disease were common among the elderly. Approximately 30% of the subjects were readmitted to hospital after the first admission; 9% had more than 2 admissions for respiratory disease during the 4-yr study period. PM10 - 2.5 was significantly associated with the second and overall admissions for respiratory disease, but not with the first admission. The adjusted relative risks for an increment of 4.2 microg/m(3) in -day average PM10 - 2.5 concentrations were 1.03 (95% confidence interval: 0.98-1.09) for the first admission, 1.22 (1.10-1.36) for the second admission, and 1.06 (1.02, 1.11) for overall admissions. There was no significant association between PM2.5 and hospital admissions for respiratory disease among the elderly. Our data suggest that (1) people with a history of respiratory admissions are at a higher risk of respiratory disease in relation to particulate air pollution in urban areas, (2) analyses based on overall rather than repeated hospital admissions lead to lower estimates of the risk of respiratory disease associated with particulate air pollution, and (3) PM10 - 2.5 has a larger effect on respiratory admissions than PM2.5.

Airborne particulate matter from primarily geologic, non-industrial sources at levels below National Ambient Air Quality Standards is associated with outpatient visits for asthma and quick-relief medication prescriptions among children less than 20 years old enrolled in Medicaid in Anchorage, Alaska

In Anchorage, Alaska, particulates with aerodynamic diameter < or = 10 micro m (PM(10)) arise primarily from natural, geologic sources, and particulates with aerodynamic diameter < or = 2.5 micro m (PM(2.5)) arise primarily from automobile emissions. The current study used a population-based time-series analysis design to evaluate the effects of daily and weekly PM(10) and PM(2.5) on respiratory health outcomes among children <20 years of age residing in Anchorage enrolled in Medicaid. All generated estimating equations models were adjusted for season, year, weekends, temperature, wind speed, and precipitation. Relative to the days with PM(10) mass concentration < or = 13 micro g/m(3), a significant 9.3% increase (RR: 1.093, 95% CI: 1.004-1.191) in the rate of outpatient visits for asthma occurred during days with PM(10) of 20-33 micro g/m(3). No further dose-response occurred for days with PM(10) > or = 34 micro g/m(3). A significant 18.1% increase (RR: 1.181, 95% CI: 1.010-1.381) in the rate of quick-relief medication prescriptions occurred during days with PM(10) of 34-60 micro g/m(3), and a 28.8% increase (RR: 1.288, 95% CI: 1.026-1.619) occurred during days with PM(10) > or = 61 micro g/m(3). Similar results for outpatient asthma visits and quick-relief medication occurred in weekly models. There were no significant associations with PM(2.5) in either daily or weekly models. These subtle but statistically significant associations suggest that non-industrial, geologic sources of PM(10) may have measurable health effects at levels below current national standards.

Total respiratory tract deposition of fine micrometer-sized particles in healthy adults: empirical equations for sex and breathing pattern

Accurate dose estimation under various inhalation conditions is important for assessing both the potential health effects of pollutant particles and the therapeutic efficacy of medicinal aerosols. We measured total deposition fraction (TDF) of monodisperse micrometer-sized particles [particle diameter (Dp) = 1, 3, and 5 μm in diameter] in healthy adults (8 men and 7 women) in a wide range of breathing patterns; tidal volumes (Vt) of 350–1500 ml and respiratory flow rates (Q̇) of 175–1,000 ml/s. The subject inhaled test aerosols for 10–20 breaths with each of the prescribed breathing patterns, and TDF was obtained by monitoring inhaled and exhaled aerosols breath by breath by a laser aerosol photometer. Results show that TDF varied from 0.12–0.25, 0.26–0.68, and 0.45–0.83 for Dp = 1, 3, and 5 μm, respectively, depending on the breathing pattern used. TDF was comparable between men and women for Dp = 1 μm but was greater in women than men for Dp = 3 and 5 μm for all breathing patterns used ( P < 0.05). TDF increased with an increase in Vt regardless of Dp and Q̇ used. At a fixed Vt TDF decreased with an increase in Q̇ for Dp = 1 and 3 μm but did not show any significant changes for Dp = 5 μm. The varying TDF values, however, could be consolidated by a single composite parameter (ω) consisting of Dp, Vt, and Q̇. The results indicate that unifying empirical formulas provide a convenient means of assessing deposition dose of particles under varying inhalation conditions.

Effects of particulate air pollution on the respiratory health of subjects who live in three areas in Kanpur, India

In this study, the authors assessed the relationship between daily changes in respiratory health and particulate levels with diameters of (a) less than 10 microm (PM10) and (b) less than 2.5 microm (PM2.5) in Kanpur, India. The subjects (N = 91) were recruited from 3 areas in Kanpur: (1) Indian Institute of Technology (Kanpur), which was a relatively clean area; (b) Vikas Nagar, a typical commercial area; and (c) finally, the residential area of Juhilal Colony. All subjects resided near to air quality monitoring sites. Air quality and peak expiratory flow rate samplings were conducted for 39 d. Once during the sampling period, lung-function tests (i.e., forced expiratory volume in 1 s, forced vital capacity) were performed on each subject. Subjects who resided at the clean site performed at predicted (i.e., acceptable) values more often than did subjects who lived at the remaining 2 sites. Subjects who lived at all 3 sites demonstrated a substantial average deficit in baseline forced vital capacity and forced expiratory volume in 1 s values. The authors used a statistical model to estimate that an increase of 100 microg/m3 of the pollutant PM10 could reduce the mean peak expiratory flow rate of an individual by approximately 3.2 l/min.

Cellular and molecular mechanisms in environmental and occupational inhalation toxicology

The central issue of this review are inflammatory changes that take place in the mucous membranes of the respiratory tract as a result of inhaled pollutants. Of particular relevance are dusts, SO(2), ozone, aldehydes und volatile organic compounds. Bioorganic pollutants, especially fragments of bacteria and fungi, occur predominantly in indoor dusts. They activate the toll-like/IL-1 receptor and lead to the activation of the transcription factor NF-κB for the release of numerous proinflammatory cytokines. Metals are predominant in ambient air dust particles. They induce the release of reactive oxygen species that cause damage to lipids, proteins and the DNA of the cell. As well as NF-κB, transcription factors that foster proliferation are activated via stress activated protein kinases. Organic compounds such as polycyclic aromatic hydrocarbons and nitroso-compounds of incomplete combustion processes activate additional via the cytosolic arylhydrocarbon receptor for detoxification enzymes. Sulphur dioxide leads to acid stress, and ozone to oxidative stress of the cell. This is accompanied by the release of proinflammatory cytokines via stress activated protein kinases. Aldehydes and volatile organic compounds activate the vanilloid receptor of trigeminal nerve fibres and induce a hyperreactivity of the mucous membrane via the release of nerve growth factors. The mechanisms described work synergistically and lead to a chronic inflammatory reaction of the mucous membranes of the upper respiratory tract that is regularly demonstrable in inhabitants of western industrial nations. It is unclear whether we are dealing here with a physiological inflammation or with an at least partially avoidable result of chronic pollutant exposure.

Enzyme activities and arylsulfatase protein content of dust and the soil source: biochemical fingerprints?

Little is known about the potential of enzyme activities, which are sensitive to soil properties and management, for the characterization of dust properties. Enzyme activities may be among the dust properties key to identifying the soil source of dust. We generated dust (27 and 7 microm) under controlled laboratory conditions from agricultural soils (0-5 cm) with history of continuous cotton (Gossypium hirsutum L.) or cotton rotated with peanut (Arachis hypogaea L.), sorghum [Sorghum bicolor (L.) Moench], rye (Secale cereale L.), or wheat (Triticum aestivum L.) under different water management (irrigated or dryland) and tillage (conservation or conventional) systems. The 27- and 7-microm dust samples showed activities of beta-glucosidase, alkaline phosphatase, and arylsulfatase, which are related to cellulose degradation and phosphorus and sulfur mineralization in soil, respectively. Dust samples generated from a loam and sandy clay loam showed higher enzyme activities compared with dust samples from a fine sandy loam. Enzyme activities of dust samples were significantly correlated to the activities of the soil source with r > 0.74 (P < 0.01). The arylsulfatase proteins contents of the soils (0.04-0.65 mg protein kg(-1) soil) were lower than values reported for soils from other regions, but still dust contained arylsulfatase protein. The three enzyme activities studied, as a group, separated the dust samples due to the crop rotation or tillage practice history of the soil source. The results indicated that the enzyme activities of dust will aid in providing better characterization of dust properties and expanding our understanding of soil and air quality impacts related to wind erosion.

Influence of relatively low level of particulate ar pollution on hospitalization for COPD in elderly people

To assess the association between relatively low levels of size-fractioned particulate matter (PM) and hospitalization for chronic obstructive pulmonary disease (COPD), we conducted a time-series analysis among elderly people 65 yr of age or more living in Vancouver between June 1995 and March 1999. Measures of thoracic PM (PM(10)), fine PM (PM(2.5)), coarse PM (PM(10-2.5)), and coefficient of haze (COH) were examined over periods varying from 1 to 7 days prior to hospital admissions. Generalized additive models (GAMs; general linear models, GLMs) were used, and temporal trends and seasonal and subseasonal cycles in COPD hospitalizations were removed by using GLM with parametric natural cubic splines. The relative risks were calculated based on an incremental exposure corresponding to the interquartile range of these measures, and were adjusted for daily weather conditions and gaseous pollutants. PM measures had a positive effect on COPD hospitalization, especially 0 to 2 days prior to the admissions, before copollutants were accounted for. For 3-day average levels of exposure the relative risk estimates were 1.13 (95% confidence interval: 1.05-1.21) for PM(10), 1.08 (1.02-1.15) for PM(2.5), 1.09 (1.03-1.16) for PM(10-2.5), and 1.05 (1.01-1.09) for COH. The associations were no longer significant when NO(2) was included in the models. We concluded that the particle-related measures were significantly associated with COPD hospitalization in the Vancouver area, where the level of air pollution is relatively low, but the effects were not independent of other air pollutants.

Association Between Particulate Air Pollution and First Hospital Admission for Childhood Respiratory Illness in Vancouver, Canada

In this study, the authors assessed the impact of particulate air pollution on first respiratory hospitalization. Study subjects were children less than 3 years of age living in Vancouver, British Columbia, who had their first hospitalization as a result of any respiratory disease (ICD-9 codes 460-519) during the period from June 1, 1995, to March 31, 1999. The authors used logistic regression to estimate the associations between ambient concentrations of particulate matter (PM) and first hospitalization. The adjusted odds ratios for first respiratory hospitalization associated with mean and maximal PM10-2.5 with a lag of 3 days were 1.12 (95% confidence interval: 0.98, 1.28) and 1.13 (1.00, 1.27). After adjustment for gaseous pollutants, the corresponding odds ratios were 1.22 (1.02, 1.48) and 1.14 (0.99, 1.32). The data indicated the possibility of harmful effects from coarse PM on first hospitalization for respiratory disease in early childhood.

PM10 and asthma medication in schoolchildren

The authors found that the use of asthma medication among elementary schoolchildren was associated with particulate pollution (particulate matter < 10 microm in aerodynamic diameter [PM10]) in a locale where PM10 consisted primarily of coarse fraction material derived from road sanding and reentrained volcanic ash. School nurses' records in 12 neighborhood schools located close to an ambient air monitoring station were abstracted, and the numbers of oral and inhaled doses of asthma medication given daily over a period of 2.5 yr were calculated. Time-series regression models, adjusted for autocorrelation, were developed, with temperature, time trend, day of the week, and month as additional variables. Regression models were estimated, and a lagged moving average of PM10 for 7, 14, 21, and 28 days was used. All models showed positive and significant coefficients for PM10 during periods when asthma medication was administered to the schoolchildren. However, the 21-day moving average was the best fit to the model.

Mitochondrial oxidant production by a pollutant dust and NO-mediated apoptosis in human alveolar macrophage

Residual oil fly ash (ROFA) is a pollutant dust that stimulates production of reactive oxygen species (ROS) from mitochondria and apoptosis in alveolar macrophages (AM), but the relationship between these two processes is unclear. In this study, human AM were incubated with ROFA or vanadyl sulfate (VOSO(4)), the major metal constituent in ROFA, with or without nitro-L-arginine methyl ester (L-NAME), diphenyleneiodonium (DPI), and mitochondrial electron transport inhibitors. Interactions among production of ROS, nitric oxide (NO), and apoptosis of AM were determined. ROFA-stimulated ROS production was attenuated by DPI, rotenone, antimycin, and NaN(3), but not by L-NAME, a pattern mimicked by VOSO(4). ROFA-induced apoptosis was inhibited by L-NAME and a caspase-3-like protease inhibitor, but not by mitochondrial inhibitors. ROFA enhanced NO-mediated increase in caspase-3-like activity. VOSO(4) had minor effects on apoptosis. Thus ROFA-stimulated production of ROS from mitochondria was independent of apoptosis of AM, which was mediated by activation of caspase-3-like proteases and NO. The pro-oxidant effect but not the proapoptotic effect of ROFA was mediated by vanadium.

Update on the health effects of outdoor air pollution

The number of studies conducted on the health effects of air pollution has increased exponentially. Important methodological advances include the application of novel observational study designs, in particular the multi-city design, and the development and application of airborne particle concentrators for use in experimental human exposure studies and toxicological studies. Experimental data are validating and providing insight into some surprising observational findings.

Infant respiratory symptoms associated with indoor heating sources

This study examined the effects of indoor heating sources on infant respiratory symptoms during the heating season of the first year of life. Mothers delivering babies between 1993 and 1996 at 12 hospitals in Connecticut and Virginia were enrolled. Daily symptom and heating source use information about their infant was obtained every 2 weeks during the first year of life. Heating sources included fireplace, wood stove, kerosene heater, and gas space heater use. Four health outcomes were analyzed by reporting period: days of wheeze, episodes of wheeze, days of cough, and episodes of cough. A large percentage of infants had at least one episode of cough (88%) and wheeze (33%) during the heating season of the first year of life. Wood stove, fireplace, kerosene heater, and gas space heater use was intermittent across the study period. In adjusted Poisson regression models controlling for important confounders, gas space heater use was associated with episodes and days of wheeze. Wood stove use was associated with total days of cough, and kerosene heater use was associated with episodes of cough. Fireplace use was not associated with any of the respiratory symptoms. Use of some heating sources appears related to respiratory symptoms in infants.

Effects of the Asian dust events on daily mortality in Seoul, Korea

The Korean peninsula has a long history of dust clouds blown by winds from the arid deserts of Mongolia and China in springtime; these are called Asian dust events. Public concern about the possible adverse effects of this dust has increased, because the dust arrives in Korea after having passed over heavily industrialized eastern China. The present study explored the effect of Asian dust events on daily mortality in Seoul, South Korea, during the period 1995-1998. We evaluated the association between daily death counts and the dust events using Poisson regression analysis, adjusted for time trends, weather variables, and the day of the week. Between 1995 and 1998, we identified 28 Asian dust days in Seoul. The estimated percentage increase in the rate of deaths from 3-day moving averages of exposure was 1.7% (95/ confidence interval: -1.6 to 5.3) for all causes, 2.2% (95% confidence interval: -3.5 to 8.3) for deaths of persons aged 65 years and older, and 4.1% (95% confidence interval: -3.8 to 12.6) for cardiovascular and respiratory causes. Our results provide weak evidence that the Asian dust events are associated with risk of death from all causes. However, the association between the dust events and deaths from cardiovascular and respiratory causes was stronger and it suggests that persons with advanced cardiovascular and respiratory disease may be susceptible to the Asian dust events.

Effects of air pollution on general practitioner consultations for upper respiratory diseases in London

OBJECTIVES

Few published studies have examined the effect of air pollution on upper respiratory conditions. Furthermore, most epidemiological studies on air pollution focus on mortality or hospital admissions as the main health outcomes, but very rarely consider the effect in primary care. If pollution effects do exist then the public health impact could be considerable because of the many patient contacts involved. We investigated the relation between air pollution and upper respiratory disease as reflected in number of consultations made at family practices in London.

METHODS

The study used non-parametric methods of analysis of time series data, adjusting for seasonal factors, day of the week, holiday effects, influenza, weather, pollen concentrations, and serial correlation.

RESULTS

It was estimated that a 10-90th percentile change (13-31 microg/m(3)) in sulphur dioxide (SO(2)) measures resulted in a small increase in numbers of childhood consultation: 3.5% (95% confidence interval (95% CI 1.4% to 5.8%). Stronger associations were found in the case of a 10-90th percentile change (16-47 microg/m(3)) in fine particles (PM(10)) in adults aged 15-64 5.7% (2.9% to 8.6%), and in adults aged 65 and over: 10.2% (5.3% to 15.3%). In general, associations were strongest in elderly people, weakest in the children, and were largely found in the winter months for these two age groups, and in the summer months for adults aged 15-64. An apparent decrease in consultations was associated with ozone concentrations but this was most pronounced in colder months when ozone concentrations were at their lowest.

CONCLUSIONS

The results suggest an adverse effect of air pollution on consultations for upper respiratory symptoms, in particular in the case of PM(10) and SO(2). The effects are relatively small; however, due to the many consultations made in primary care, the impact on demand for services could be considerable.

Monitoring of airborne particulate matter during the eruption of Soufrière Hills Volcano, Montserrat

A programme of air quality monitoring was devised to investigate concentrations and behaviour of repirable ash in the air on Montserrat. Sampling strategies used were short environmental tests, occupational tests, and continuous environmental monitoring in periods of both high and low volcanic activity. The results obtained between September 1996 and July 1999 allow comparison of the contributions made to airborne particles by different eruptive styles. Vulcanian explosions and ash-venting increased average background concentrations (c.30 µg m -3) of airbrne particles (≤10 µm in diameter) by up to a factor of ten. Large dome collapses released large amounts of ash into the atmosphere in an extremely sort time and airborne particle concentrations reached more than 600 µg m-3. Aggregates of ash particles broke up on impact wth the gournd and ash re-suspension by wind caused airborne particle concentrations of approximately 250 µg m-3. which were sometimes significantly higher than those caused by tephra fallout. Airborne particle concentration decreased with distance from the ash source, and wind an drain effectively removed ash from the atmosphere. Generally, airborne particle concentrations in inhabited areas of Montserrat remained low, even during elevated volcanic activity, when volcanic products were carried away by winds

What do epidemiologic findings tell us about health effects of environmental aerosols?

In the last 10 years there has been an abundance of new epidemiological studies on health effects of particulate air pollution. The overall evidence suggests that fine particulate pollution can be an important risk factor for cardiopulmonary disease. Long-term, repeated exposure to fine particulate air pollution may increase the risk of chronic respiratory disease and the risk of cardiopulmonary mortality. Short-term exposures exacerbate existing cardiovascular and pulmonary disease and increase the risk of becoming symptomatic, requiring medical attention, or even dying. This paper outlines the results of the basic epidemiologic studies and briefly reviews and discusses recent studies that have looked at specific physiologic health endpoints in addition to lung function. A few recent, mostly exploratory pilot studies, have observed particulate pollution associations with blood plasma viscosity, heart rate, heart rate variability, and indicators of bone marrow stimulation. A systemic response to particulate-related pulmonary inflammation remains somewhat speculative. The epidemiologic evidence, nevertheless, seems consistent with the hypothesis that particle-induced pulmonary inflammation, cytokine release, and altered cardiac autonomic function may be part of the pathophysiological mechanisms or pathways linking particulate pollution with cardiopulmonary disease.

The interaction between particulate air pollution and allergens in enhancing allergic and airway responses

Although the detrimental effects of air pollution on human health have been brought widely to public notice, it appears that less attention has been given to the potential role of toxic air pollutants in the induction of allergic conditions such as asthma, rhinoconjunctivitis, and atopic eczema. A number of large epidemiologic studies have shown that people exposed to intense motor vehicle traffic and its associated emissions are at major risk for allergic symptoms, reduced lung function, and increased sensitization to common airborne allergens. Several laboratory-based studies have demonstrated that particulate air pollutants emitted from motor vehicles can induce allergic inflammation, enhance IgE responses, and increase airway hyperresponsiveness, which could provide an underlying mechanism for the increasing prevalence of allergic diseases. This article reviews the evidence that supports the causative link between particulate air pollution and the sharp increase in the prevalence of type I allergies in developed countries.

Genotoxic effects of carbon black particles, diesel exhaust particles, and urban air particulates and their extracts on a human alveolar epithelial cell line (A549) and a human monocytic cell line (THP-1)

The possible genotoxicity of small particulate matter has been under investigation for the last 10 years. Diesel exhaust particles (DEP) are considered as "probably carcinogenic" (IARC group 2A) and a number of studies show genotoxic effects of urban particulate matter (UPM). Carbon black (CB) is carcinogenic in rats. In this study the cytotoxic and genotoxic potency of these three particle types was investigated by exposing human cells (A549 and THP-1 cell lines) in vitro to CB, DEP (SRM 1650, NIST), and UPM (SRM 1648, NIST) for 48 hr. Cytotoxicity was assessed using the Alamar Blue assay, whereas genotoxicity was assessed using the single-cell gel electrophoresis (comet assay). The particles were characterized with regard to their mean diameter in tissue culture medium (CB 100 nm, DEP 400 nm, UPM 2 microm), their total carbon content (CB 99%, DEP 85%, UPM 15%), and their acid-soluble metal composition (UPM >> CB approximately DEP). The concentrations ranged from 16 ng/ml to 16 microg/ml for cytotoxicity tests and from 16 ng/ml to 1.6 microg/ml for genotoxicity tests. In both assays, paraquat was used as a reference chemical. The CB, DEP, and UPM particles showed no significant cytotoxicity. However, all three particles were able to cause significant DNA damage, although to a different extent in the two cell lines. The genotoxicity of washed particles and dichloromethane extracts was also investigated. In THP-1 cells CB washed particles and DEP extracts caused significant DNA damage. This difference in effect may be related to differences in size, structure, and composition of the particles. These results suggest that CB, DEP, and UPM are able to cause DNA damage and, therefore, may contribute to the causation of lung cancer. More detailed studies on influence of size, structure, and composition of the particles are needed.

Suspended particulate matter in indoor air: adjuvants and allergen carriers

The overall purpose of this study was to investigate how airborne house dust particles may contribute to an allergic immune response, and thereby also to asthma and other respiratory symptoms. The following aims were set: first, to quantify and characterize indoor suspended particulate matter (SPM) with regard to amount, as well as elemental and size distribution, second, to identify possible mechanisms by which SPM may affect the allergic immune response. A vast majority of the particles in SPM samples from homes in Oslo were found to be less than 2.5 microm in diameter. This PM(2.5) fraction contained, in addition to a large amount of sulfur aerosols and silicates, a lot of soot particles. Most of these were less than 1 microm in diameter. Using an immunogold labeling technique, we found that these soot particles carried cat, dog and birch allergens on their surface. These results show that indoor SPM contains a lot of potential allergen carriers, i.e. soot particles (carbon aggregates), most of them less that 1 microm in diameter and therefore able to transport allergens deep into the respiratory tree. We further found that diesel exhaust particles (DEP), which is likely the main soot component of SPM, adsorbed several well-known allergens in vitro. Furthermore, SPM was found to elicit a local lymph node inflammatory response, and to have an adjuvant activity on the production of IgE antibodies to ovalbumin (OA).

Epidemiology of fine particulate air pollution and human health: biologic mechanisms and who's at risk?

This article briefly summarizes the epidemiology of the health effects of fine particulate air pollution, provides an early, somewhat speculative, discussion of the contribution of epidemiology to evaluating biologic mechanisms, and evaluates who's at risk or is susceptible to adverse health effects. Based on preliminary epidemiologic evidence, it is speculated that a systemic response to fine particle-induced pulmonary inflammation, including cytokine release and altered cardiac autonomic function, may be part of the pathophysiologic mechanisms or pathways linking particulate pollution with cardiopulmonary disease. The elderly, infants, and persons with chronic cardiopulmonary disease, influenza, or asthma are most susceptible to mortality and serious morbidity effects from short-term acutely elevated exposures. Others are susceptible to less serious health effects such as transient increases in respiratory symptoms, decreased lung function, or other physiologic changes. Chronic exposure studies suggest relatively broad susceptibility to cumulative effects of long-term repeated exposure to fine particulate pollution, resulting in substantive estimates of population average loss of life expectancy in highly polluted environments. Additional knowledge is needed about the specific pollutants or mix of pollutants responsible for the adverse health effects and the biologic mechanisms involved.

Particle size distribution and its elemental composition in the ambient air of Delhi

This study examines the chemical composition of PM10, the thoracic fraction of the atmospheric particulate matter. An eight-stage Anderson impactor is used to separate the PM10 from other fractions with different aerodynamic behaviour at three different area representative sites in Delhi from February to May 1998. PM10 particulate are subdivided into two fractions, coarse (> 2.1-10 microns) and fine (< 2.1 microns). The concentrations of major heavy metals such as Pb, Zn, Cd, Ni, and Fe are determined by atomic absorption spectrophotometer. The average concentration of coarse fraction of PM10 is found to be 68.3 +/- 17 micrograms/m3 while the fine fraction of PM10 is 71.3 +/- 15 micrograms/m3 for Delhi. Metal concentration (except Fe) in fine fraction exceeds by a factor of up to 6, as compared to that in the coarse fraction. In order to identify the major sources of fine and coarse fraction of PM10, principle component analysis (PCA) was undertaken and three major sources were identified, namely vehicular emissions, industrial emission, and soil resuspension.

Epidemiology of fine particulate air pollution and human health: biologic mechanisms and who's at risk?

This article briefly summarizes the epidemiology of the health effects of fine particulate air pollution, provides an early, somewhat speculative, discussion of the contribution of epidemiology to evaluating biologic mechanisms, and evaluates who's at risk or is susceptible to adverse health effects. Based on preliminary epidemiologic evidence, it is speculated that a systemic response to fine particle-induced pulmonary inflammation, including cytokine release and altered cardiac autonomic function, may be part of the pathophysiologic mechanisms or pathways linking particulate pollution with cardiopulmonary disease. The elderly, infants, and persons with chronic cardiopulmonary disease, influenza, or asthma are most susceptible to mortality and serious morbidity effects from short-term acutely elevated exposures. Others are susceptible to less serious health effects such as transient increases in respiratory symptoms, decreased lung function, or other physiologic changes. Chronic exposure studies suggest relatively broad susceptibility to cumulative effects of long-term repeated exposure to fine particulate pollution, resulting in substantive estimates of population average loss of life expectancy in highly polluted environments. Additional knowledge is needed about the specific pollutants or mix of pollutants responsible for the adverse health effects and the biologic mechanisms involved.

Investigation of factors which might indicate susceptibility to particulate air pollution

OBJECTIVES

To determine whether previous symptoms or recognized risk factors of cardiovascular ill health, are associated with an increased likelihood of adverse health effects related to particulate air pollution.

METHODS

Cardiovascular event rates were studied relative to urban concentrations of particulate air pollution and baseline risk factors. The Edinburgh artery study consisted of a cohort of 1592 subjects aged 55-74 and was followed up to the end of March 1998 for a median of 10 years resulting in about 5 million person-days of observation. Baseline measurements included plasma fibrinogen and blood and plasma viscosity. A nested case-control approach was used to investigate a possible interaction between effects of these selected baseline risk factors and particulate air pollution, on subsequent event rates.

RESULTS

During the follow up period there were 343 fatal and non-fatal myocardial infarctions or strokes. Trends in adverse cardiovascular outcomes related to pollution were identified among subjects belonging to the highest baseline quintile of plasma fibrinogen. Evidence for interactions between concentrations of particulate pollution and fibrinogen was not established at conventional levels of significance.

CONCLUSIONS

People with high concentrations of plasma fibrinogen might be more susceptible to adverse cardiovascular effects of particulate air pollution, but limitations of power mean that evidence relating to such an interaction is not conclusive. A range of cardiopulmonary risk factors warrant investigation in relation to possible susceptibility to air pollution.

Air pollution and daily mortality in the Coachella Valley, California: a study of PM10 dominated by coarse particles

Many epidemiological studies provide evidence of an association between airborne particles, measured as PM10 (particulate matter less than 10 microm in diameter), and daily morbidity and mortality. Most of these studies have been conducted in urban areas where PM10 consists primarily of fine particles (<2.5 microm in diameter). Few studies have investigated impacts associated with coarse mode particles (>2.5 microm in diameter). We investigated associations between PM10 and daily mortality in the Coachella Valley, a desert resort and retirement area east of Los Angeles, where coarse particles of geologic origin typically comprise approximately 50-60% of PM10 and can exceed 90% during wind events. Our analysis utilized daily data on mortality from 1989 through 1992 as well as several pollutant and meteorological variables, including PM10, nitrates, sulfates, ozone, nitrogen dioxide, carbon monoxide, temperature, and relative humidity. Outcome variables included several measures of daily mortality, including all-cause, cardiovascular and respiratory mortality, and counts of deaths for those above age 50. Multivariate Poisson regression models were used to explain these health endpoints, controlling for temperature, humidity, day of the week, season, and time, using locally weighted smoothing techniques. The analysis indicated statistically significant associations between PM10 (2- or 3-day lags) and each measure of mortality. The results were robust to various model specifications, correction for autocorrelation and overdispersion, and analysis of influential observations. A 10 microg/m3 change in daily PM10 was associated with an approximately 1% increase in mortality, which is of similar magnitude to particle-associated impacts identified in urban areas. Thus, our findings provide evidence for a mortality effect of PM10 in an area where the particulate mass is dominated by coarse particles.

Asthma in the inner city: a growing public health problem

Asthma in the inner city impacts people of all ages and is most pronounced in African Americans and other minorities. During the past decade, the prevalence of asthma has increased by 42%, a rate consistently higher in African Americans. Along with the increase in asthma prevalence, the costs associated with this disease have also risen dramatically. In addition, asthma is the leading cause of school absenteeism and also contributes to lost productivity. This article focuses on the epidemiology of asthma in urban areas and identifies various risk factors that are important in achieving control of this disease. Suggestions for future interventions are discussed.

Air pollution and asthma

Asthma is a disease syndrome that has captured a great deal of attention for several years. One of the perplexing aspects to asthma is that the prevalence is increasing in most industrialized countries. The reasons for this widespread increase are largely unknown. Another aspect of industrialization is the persistence of air pollution in urban areas. Because much air pollution is due to vehicles, no solution appears in sight. The topic of this article is the association between air pollution and various signs and symptoms of asthma. Air pollution is convincingly associated with many signs of asthma aggravation. These include pulmonary function decrements, increased bronchial hyperresponsiveness, visits to emergency departments, hospital admissions, increased medication use and symptom reporting, inflammatory changes, interactions between air pollution and allergen challenges, and immune system changes. With the exception of exposure to environmental tobacco smoke, common air pollutants have not been shown to cause asthma. It seems prudent for clinicians to counsel their patients about the potential risks of asthma aggravation from common outdoor air pollutants.

An association between fine particles and asthma emergency department visits for children in Seattle

Asthma is the most common chronic illness of childhood and its prevalence is increasing, causing much concern for identification of risk factors such as air pollution. We previously conducted a study showing a relationship between asthma visits in all persons < 65 years of age to emergency departments (EDs) and air pollution in Seattle, Washington. In that study the most frequent zip codes of the visits were in the inner city. The Seattle-King County Department of Public Health (Seattle, WA) subsequently published a report which showed that the hospitalization rate for children in the inner city was over 600/100,000, whereas it was < 100/100,000 for children living in the suburbs. Therefore, we conducted the present study to evaluate whether asthma visits to hospital emergency departments in the inner city of Seattle were associated with outdoor air pollution levels. ED visits to six hospitals for asthma and daily air pollution data were obtained for 15 months during 1995 and 1996. The association between air pollution and childhood ED visits for asthma from the inner city area with high asthma hospitalization rates were compared with those from lower hospital utilization areas. Daily ED counts were regressed against fine particulate matter (PM), carbon monoxide (CO), sulfur dioxide, and nitrogen dioxide using a semiparametric Poisson regression model. Significant associations were found between ED visits for asthma in children and fine PM and CO. A change of 11 microg/m3 in fine PM was associated with a relative rate of 1.15 [95% confidence interval (CI), 1.08-1.23]. There was no stronger association between ED visits for asthma and air pollution in the higher hospital utilization area than in the lower utilization area. These findings were seen when estimated PM2.5 concentrations were below the newly adopted annual National Ambient Air Quality Standard of 15 microg/m3.

An association between fine particles and asthma emergency department visits for children in Seattle

Asthma is the most common chronic illness of childhood and its prevalence is increasing, causing much concern for identification of risk factors such as air pollution. We previously conducted a study showing a relationship between asthma visits in all persons < 65 years of age to emergency departments (EDs) and air pollution in Seattle, Washington. In that study the most frequent zip codes of the visits were in the inner city. The Seattle-King County Department of Public Health (Seattle, WA) subsequently published a report which showed that the hospitalization rate for children in the inner city was over 600/100,000, whereas it was < 100/100,000 for children living in the suburbs. Therefore, we conducted the present study to evaluate whether asthma visits to hospital emergency departments in the inner city of Seattle were associated with outdoor air pollution levels. ED visits to six hospitals for asthma and daily air pollution data were obtained for 15 months during 1995 and 1996. The association between air pollution and childhood ED visits for asthma from the inner city area with high asthma hospitalization rates were compared with those from lower hospital utilization areas. Daily ED counts were regressed against fine particulate matter (PM), carbon monoxide (CO), sulfur dioxide, and nitrogen dioxide using a semiparametric Poisson regression model. Significant associations were found between ED visits for asthma in children and fine PM and CO. A change of 11 microg/m3 in fine PM was associated with a relative rate of 1.15 [95% confidence interval (CI), 1.08-1.23]. There was no stronger association between ED visits for asthma and air pollution in the higher hospital utilization area than in the lower utilization area. These findings were seen when estimated PM2.5 concentrations were below the newly adopted annual National Ambient Air Quality Standard of 15 microg/m3.

The environment and asthma in U.S. inner cities

The prevalence and severity of asthma has increased in the last 20 years, and the greatest increase has been seen among children and young adults living in U.S. inner cities. The reasons for this increase are obviously complex, but include environmental exposures to allergens and pollutants, changing patterns of medication, and the psychosocial stresses of living in poor inner-city neighborhoods. This paper presents an overview of environmental, immunologic, and genetic factors associated with asthma morbidity and mortality. This overview can be used to provide a framework for designing an interdisciplinary research program to address the complexities of asthma etiology and exacerbation. The strongest epidemiologic association has been found between asthma morbidity and the exposure of immunologically sensitive asthmatic patients to airborne allergens. Our current understanding of the process of sensitization suggests that there is a strong genetic predisposition to form IgE to allergenic proteins on airborne particles. Much of this work has been conducted with animal models, but in a number of instances, specific confirmation has been reported in humans. Sensitized individuals respond to inhaled exposure with immediate mast-cell dependent inflammation that may be augmented by pollutant particles, especially diesel exhaust particles. Relatively little is known about the methods of assessing exposure to airborne pollutants, especially biologically active particulates. However, to examine the relationship of morbidity in genetically predisposed individuals, it will be important to determine the most relevant method of making this assessment.