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PubMed1996

Industrial atmospheric pollution, historical land use patterns and mortality.

BACKGROUND: The measurement of atmospheric pollution for epidemiological studies is problematic. This study presents a new proxy measure of atmospheric pollution of industrial origin and uses it to determine, at electoral ward level, the relationship between atmospheric pollution and all-cause mortality. METHODS: All-cause Standardized Mortality Ratios (SMR), all ages, and for persons under 65 years for the period 1984-1988, proportions of land in each ward utilized by industrial works (the proxy for atmospheric pollution) and levels of socioeconomic deprivation of the ward residents were compared in 104 electoral wards. RESULTS: The all-age SMR in the 22 wards containing the largest proportions of industrial land (113) was 9.7 per cent higher than the SMR (103) in the 60 wards with no industrial land. The under 65 years SMR in the 22 highly industrialized wards (120) was 22.4 per cent higher than the SMR (98) in the wards with no industrial land. After matching the levels of deprivation, the all-age SMR in the 15 wards containing over 10 per cent industrial land (116) was significantly higher than the SMR in 15 wards containing no industrial land (108); corresponding figures for the under 65 years SMR were 135 and 118. CONCLUSIONS: A greater proportion of industrial land in a ward is associated with a higher mortality of the ward residents, even after controlling for the level of socio-economic deprivation of the residents. The association between deprivation and mortality is stronger than the association between atmospheric pollution and mortality. There is an urgent need for better measures of atmospheric pollution which are usable in epidemiological studies.

Adolescent↗
PubMed2001

Canines as sentinel species for assessing chronic exposures to air pollutants: part 2. Cardiac pathology.

The principal objective of this study is to evaluate by light and electron microscopy (LM, EM) the heart tissues in stray southwest and northeast metropolitan Mexico City (SWMMC, NEMMC) dogs and compare their findings to those from 3 less polluted cities (Cuernavaca, Tlaxcala, and Tuxpam). Clinically healthy mongrel dogs, including 109 from highly polluted SWMMC and NEMMC, and 43 dogs from less polluted cities were studied. Dogs residing in cities with lower levels of pollutants showed little or no cardiac abnormalities. Mexico City and Cuernavaca dogs exhibited LM myocardial alterations including apoptotic myocytes, endothelial and immune effector cells, degranulated mast cells associated with scattered foci of mononuclear cells in left and right ventricles and interventricular septum, and clusters of adipocytes interspersed with mononuclear cells. Vascular changes included scattered polymorphonuclear leukocytes (PMN) margination and microthrombi in capillaries, and small venous and arteriolar blood vessels. Small veins exhibited smooth muscle cell hyperplasia, and arteriolar blood vessels showed deposition of particulate matter (PM) in the media and adventitia. Unmyelinated nerve fibers showed endoneural and epineural degranulated mast cells. EM examination of myocardial mast cells showed distended and abundant rough endoplasmic reticulum with few secretory granules. Myocardial capillaries exhibited fibrin deposition and their endothelial cells displayed increased luminal and abluminal pinocytic activity and the formation of anemone-like protrusions of the endothelium into the lumen. A close association between myocardial findings, lung epithelial and endothelial pathology, and chronic inflammatory lung changes was noted. The myocardial changes described in dogs exposed to ambient air pollutants may form the basis for developing hypothesis-driven mechanistic studies that might explain the epidemiological data of increased cardiovascular morbidity and mortality in people exposed to air pollutants.

Air Pollutants↗
PubMed1997

Air pollution and hospital admissions for respiratory causes in Minneapolis-St. Paul and Birmingham.

We investigated the association between air pollution and hospital admissions for chronic obstructive pulmonary disease and pneumonia among the elderly in Minneapolis-St. Paul, MN, and Birmingham, AL, over the period January 1, 1986, to December 31, 1991. Pollutants included in our analyses were PM10 (particulate matter less than 10 microns in aerodynamic diameter), SO2, NO2, O3, and CO in Minneapolis-St. Paul, and PM10, O3, and CO in Birmingham. After adjusting for temperature, day of week, season, and temporal trends, we found little evidence of association between air pollution and hospital admissions for respiratory causes in Birmingham. In contrast, we found that air pollution was associated with hospital admissions for respiratory causes in Minneapolis-St. Paul. Among the individual pollutants, O3 was most strongly associated with admissions (estimated increase in hospital admissions associated with a 15-parts-per-billion increase in O3 on the previous day = 5.15%; 95% confidence interval = 2.36-7.94%), and this association was robust in the sense that it was little affected by the simultaneous consideration of other pollutants. PM10, SO2, and NO2 were also associated with hospital admissions, although none could be singled out as being more important than the others.

Aged↗
PubMed2000

Associations between outdoor air pollutants and hospitalization for respiratory diseases.

The concentration of particulate matter in outdoor air, as indicated by daily measures of particulate matter 10 microm in diameter (PM10) in many cities, has been found to be associated with the daily number of deaths and hospital admissions in these cities. To understand this association better, we studied the daily number of hospital admissions for respiratory diseases and the concentrations of eight pollutants in ambient air, during a period of 38 months, in an area with cold winters and air pollution that comes mainly from motor vehicles. We estimated the changes in risk of hospitalization by interquartile increases in pollutant concentrations by Poisson regression analyses. Controlling for periodic trends and weather, the relative risk of hospitalization associated with an interquartile increase of PM10 was 1.038 [95% confidence interval (CI) = 0.991-1.087]. In contrast, the relative risk associated with benzene was 1.105 (95% CI = 1.047-1.166). In a two-pollutant model, the relative risk estimates were 1.014 (95% CI = 0.966-1.063) for PM10 and 1.090 (95% CI = 1.031-1.153) for benzene. We evaluated other two- and three-pollutant models and concluded that pollutants other than PM10 are more strongly associated with hospital admissions for respiratory diseases.

Air Pollutants↗
PubMed2002

Outdoor air pollution and acute respiratory infections among children in developing countries.

Acute respiratory infections (ARIs) are the most common cause of illness and death in children in the developing world. This review focuses on outdoor air pollutants associated with pediatric ARI mortality and morbidity. Studies were identified using MEDLINE and other electronic databases. Four studies showed an increase in infant mortality in relation to outdoor air pollution. Short-term follow-up and time-series studies suggest that air pollutants act as risk factors for respiratory infection. Air pollution exposure increases the incidence of upper- and lower-respiratory infections in children. Because complex pollution mixtures are present in the studied urban areas, pollutant levels at which ARI risk would be expected to increase cannot be determined. Children may be at greater risk, given the poor environmental and nutritional conditions prevalent in developing countries.

Acute Disease↗
PubMed2004

Traffic related pollutants in Europe and their effect on allergic disease.

PURPOSE OF REVIEW: The prevalence and incidence of allergic diseases have increased in Europe during the last decades, as in most industrialized countries in other parts of the world. Persistent exposure to traffic related air pollution and especially particulate matter from motor vehicles has often been discussed as one of the factors responsible for this increase. This view seems to be supported by recent human and animal laboratory-based studies, which have shown that particulate pollutants, and in particular diesel exhaust particles, can enhance allergic inflammation and induce the development of allergic immune responses. However, the results from epidemiologic research provide a more complex picture. RECENT FINDINGS: It has been clearly shown in many studies that traffic related air pollution contributes to increased mortality risk; in particular in relation to cardiopulmonary causes. Traffic related air pollution also increases the risk of non-allergic respiratory symptoms and disease. However, for allergic symptoms and illnesses like asthma, allergic rhinitis, atopic dermatitis, wheeze, and allergic sensitization less consistent results have been found. This is the reason why the World Health Organisation concludes cautiously that traffic related air pollution may increase the risk of allergy development and may exacerbate symptoms in particular in susceptible subgroups. This review concentrates on recent epidemiologic studies on the long-term effects of exposure to traffic related air pollution on allergic disease in Europe. SUMMARY: In conclusion, the evidence for an increased risk for asthma and hay fever still is weak but seems to be strengthened a little. However, many questions are left open.

Air Pollutants↗
PubMed2005

Ambient air pollution and respiratory emergency department visits.

BACKGROUND: A number of emergency department studies have corroborated findings from mortality and hospital admission studies regarding an association of ambient air pollution and respiratory outcomes. More refined assessment has been limited by study size and available air quality data. METHODS: Measurements of 5 pollutants (particulate matter [PM10], ozone, nitrogen dioxide [NO2], carbon monoxide [CO], and sulfur dioxide [SO2]) were available for the entire study period (1 January 1993 to 31 August 2000); detailed measurements of particulate matter were available for 25 months. We obtained data on 4 million emergency department visits from 31 hospitals in Atlanta. Visits for asthma, chronic obstructive pulmonary disease, upper respiratory infection, and pneumonia were assessed in relation to air pollutants using Poisson generalized estimating equations. RESULTS: In single-pollutant models examining 3-day moving averages of pollutants (lags 0, 1, and 2): standard deviation increases of ozone, NO2, CO, and PM10 were associated with 1-3% increases in URI visits; a 2 microg/m increase of PM2.5 organic carbon was associated with a 3% increase in pneumonia visits; and standard deviation increases of NO2 and CO were associated with 2-3% increases in chronic obstructive pulmonary disease visits. Positive associations persisted beyond 3 days for several of the outcomes, and over a week for asthma. CONCLUSIONS: The results of this study contribute to the evidence of an association of several correlated gaseous and particulate pollutants, including ozone, NO2, CO, PM, and organic carbon, with specific respiratory conditions.

Adolescent↗
PubMed2003

Possible effects of polychlorinated biphenyls and organochlorinated pesticides on the thyroid after long-term exposure to heavy environmental pollution.

The purpose of this work was to study the effects of high environmental exposure to polychlorinated biphenyls (PCBs) and other organochlorines on the thyroid. Thyroid volume, hypoechogenicity and nodules (by ultrasound), presence of antithyroid peroxidase (anti-TPO) antibodies, and abnormal thyroid-stimulating hormone (TSH) levels in serum (by radioimmunoassay) were examined in 101 adults from the PCB-polluted area in 360 controls. Serum levels of PCBs, hexachlorobenzene, gamma-hexachlorocyclohexane (HCH), p,p'-DDT(1,1,1-trichloro-2,2'-bis(p-chlorophenyl)ethane), and p,p'-DDE(1,1-dichloro-2,2'-bis(p-chlorophenyl)ethene) were measured by high-resolution gas chromatography. Very high levels of PCBs were found in the polluted area (7300 +/- 871 ng/g lipids) compared with controls (2045 +/- 147 ng/g). Positive correlations (P < 0.001) were found between the levels of all organochlorines and their total except for hexachlorocyclohexane (HCH). In the polluted area, the highest thyroid volumes (18.7 +/- 2.32 mL; mean +/- SE) were clustered among 23 subjects (17 males and six females) with PCB levels above 10,000 ng/g (range 10,000-58,667 ng/g). In the remaining 438 subjects the thyroid volume was 14.2 +/- 0.29 mL. These data suggest that there might be a threshold serum PCB level of approximately 10,000 ng/g that may influence the thyroid volume. A two-way ANOVA showed that all thyroid volumes in the polluted area were significantly higher (P < 0.001) than in the control area. In males from the polluted area, the frequencies of thyroid hypoechogenicity, thyroid nodules, positive anti-TPO, and abnormal TSH level were higher than in males from the control area, whereas such differences were not observed in females. Increased thyroid volume and indicators of potential thyroid dysfunction were associated with long-term environmental exposure to PCBs. These effects on the thyroid were confined to subjects with PCB levels above 10,000 ng/g of lipid (thyroid volume) and to males from the polluted area (thyroid hypoechogenicity, thyroid nodules, positive anti-TPO, and abnormal TSH).

Adult↗
PubMed2006

Do gender, education, and income modify the effect of air pollution gases on cardiac disease?

OBJECTIVE: We sought to determine whether gender, education, and income influence the susceptibility to ambient air pollution. METHODS: We determined the association between daily cardiac hospitalizations and daily concentrations of gaseous air pollutants in 10 large Canadian cities using time-series analyses adjusted for day-of-the week, temperature, barometric pressure, relative humidity. RESULTS: Percentage increases in hospitalization associated with an increase in air pollution equivalent to its mean value were statistically significant for ozone, carbon monoxide and nitrogen dioxide individually (P < 0.05) and the combined pollutant effect was 8.5% (95% confidence interval: 1.8, 14.6). The air pollution-cardiac disease association was not significantly influenced by gender or community level of education or income. CONCLUSION: Short-term changes in air pollution may adversely affect cardiac disease but gender, and community education and income do not accurately identify those with increased susceptibility.

Air Pollution↗
PubMed1997

Anaesthetic pollution. Potential sources, their identification and control.

Anaesthetic gases escape into the ambient air mainly from the anaesthetic breathing system but there are many other important sources of anaesthetic pollution. These include the filling of vaporisers, inhalational induction techniques, leaks around the patient's face mask, leaks from monitoring equipment and loose-fitting or perishing equipment. The control of substances hazardous to health (COSHH) regulations together with the recent implementation of the occupational exposure standards (OES) for anaesthetic gases require that any risk to health workers from anaesthetic exposure be assessed, control measures implemented, the environment monitored and OES not exceeded. The installation of costly scavenging equipment is believed to have reduced the levels of pollution in operating theatres, but several independent reports suggest that their use has not been wholly effective. Many sources of pollution remote from scavenging equipment may be responsible for the ineffective control of anaesthetic pollution. During an initial COSHH assessment in our hospital, using an infra-red analyser specifically designed for leak testing and background monitoring, we have identified several controllable sources of pollution. These included leaks from an ill-fitting face mask, loose connections in the anaesthetic breathing system, leaks from the laryngeal mask at the end of the operation and a leak of more than 5400 ppm N2O was found near the unscavenged gas outlet at the back of the multigas monitor. Leak testing, using infra-red analysers with their rapid response, has been recommended as an important aid in the identification of hidden sources of pollution, most of which we believe are amenable to control and remedy.

Air Pollutants, Occupational↗
PubMed2006

Novel upper meta-pathway extradiol dioxygenase gene diversity in polluted soil.

For the determination of the catabolic community diversity that is related to biodegradation potential, we developed a protocol for the assessment of catabolic marker genes in polluted soils. Primers specific to upper pathway extradiol dioxygenase genes were designed which amplified a 469-bp product from Sphingomonas sp. HV3. The constructed primers were used in PCR amplification of upper pathway ring cleavage genes from DNA directly isolated from a mineral oil polluted landfill site, a mineral oil landfarming site and a birch rhizosphere-associated soil that was either artificially polluted with a PAH mixture or not polluted. Amplicons were cloned and subjected to restriction fragment length polymorphism analysis dividing the HhaI-digested products into operational taxonomic units. Altogether 26 different operational taxonomic units were detected with the sequence similarity to known catabolic genes of Alpha-, Beta-, and Gammaproteobacteria. Phylogenetic analysis divided the operational taxonomic units from the polluted soils into seven clusters. Two contained exclusively sequences with no close homologues in the database, therefore representing novel catabolic genes. This large proportion of novel extradiol sequences shows that there is an extensive unknown catabolic diversity in polluted environments.

Bacteria↗
PubMed2006

Detection of human-derived fecal pollution in environmental waters by use of a PCR-based human polyomavirus assay.

Regulatory agencies mandate the use of fecal coliforms, Escherichia coli or Enterococcus spp., as microbial indicators of recreational water quality. These indicators of fecal pollution do not identify the specific sources of pollution and at times underestimate health risks associated with recreational water use. This study proposes the use of human polyomaviruses (HPyVs), which are widespread among human populations, as indicators of human fecal pollution. A method was developed to concentrate and extract HPyV DNA from environmental water samples and then to amplify it by nested PCR. HPyVs were detected in as little as 1 microl of sewage and were not amplified from dairy cow or pig wastes. Environmental water samples were screened for the presence of HPyVs and two additional markers of human fecal pollution: the Enterococcus faecium esp gene and the 16S rRNA gene of human-associated Bacteroides. The presence of human-specific indicators of fecal pollution was compared to fecal coliform and Enterococcus concentrations. HPyVs were detected in 19 of 20 (95%) samples containing the E. faecium esp gene and Bacteroides human markers. Weak or no correlation was observed between the presence/absence of human-associated indicators and counts of indicator bacteria. The sensitivity, specificity, and correlation with other human-associated markers suggest that the HPyV assay could be a useful predictor of human fecal pollution in environmental waters and an important component of the microbial-source-tracking "toolbox."

Animals↗
PubMed1979

Comparison of antibodies in marine fish from clean and polluted waters of the New York Bight: relative levels against 36 bacteria.

Fish from polluted waters are subject to increased prevalence of disease. Because they respond to bacterial pathogens by producing serum antibodies, it was possible to construct a seasonal serological record in three fish species from clean and polluted waters of the New York Bight. Antibody levels were determined by testing sera for agglutinating activity against 36 strains of bacteria. Evaluation of 5,100 antibody titrations showed the following. During warm months, summer flounder (Paralichthys dentatus) from the polluted area had significantly higher antibody levels and antibody to a greater diversity of bacteria than fish from the unpolluted area. Weakfish (Cynoscion regalis) from the same polluted area shared with summer flounder raised titers to many bacteria. The greatest proportion of raised titers was against Vibrio species, although prominent titers were also seen against Aeromonas salmonicida and Haemophilus piscium, bacteria usually associated with diseases in freshwater but not marine fish. Differences between polluted and clean waters were not as evident in winter flounder (Pseudopleuronectes americanus) during cold months. This could be due, in part, to reduced antibody production at colder temperatures. The data illustrate the usefulness of the serum antibody record in identifying environmental exposure to bacteria in marine fish and indicate that the polluted New York Bight apex has increased levels and diversity of bacteria during warm months.

Animals↗
PubMed1990

Air pollution and cause specific mortality in Athens.

STUDY OBJECTIVE: The aim was to investigate the reported association between air pollution and cause specific mortality in the city of Athens. DESIGN: Cause specific mortality was contrasted between 199 d with high values of air pollution and 2*199 comparison days with low pollution, matched in a 1:2 ratio on the basis of various confounding factors. Statistical analysis was done, taking matching into account, using analysis of variance for randomised blocks. SETTING: The study was confined to the city of Athens, using data obtained between 1975 and 1982. PARTICIPANTS: Cause of death was assessed in all 25 138 persons dying in the 3*199 d studied. MEASUREMENTS AND MAIN RESULTS: Causes of death were evaluated blindly by two medically qualified investigators on the basis of information in the death certificates. Mortality was generally higher during the high pollution days but the difference was more pronounced and more significant for respiratory conditions, even though the number of deaths in this category was smaller than the corresponding numbers in the other two categories examined (cardiac and "other" deaths). CONCLUSION: The results show that the short term association between air pollution and overall mortality in Athens is likely to be causal, since it is particularly evident with respect to respiratory conditions, for which a biological air pollution link is more plausible.

Air Pollution↗
PubMed2006

Respiratory health and individual estimated exposure to traffic-related air pollutants in a cohort of young children.

OBJECTIVES: To estimate long-term exposure to traffic-related air pollutants on an individual basis and to assess adverse health effects using a combination of air pollution measurement data, data from geographical information systems (GIS) and questionnaire data. METHODS: 40 measurement sites in the city of Munich, Germany were selected at which to collect particulate matter with a 50% cut-off aerodynamic diameter of 2.5 microm (PM2.5) and to measure PM2.5 absorbance and nitrogen dioxide (NO2). A pool of GIS variables (information about street length, household and population density and land use) was collected for the Munich metropolitan area and was used in multiple linear regression models to predict traffic-related air pollutants. These models were also applied to the birth addresses of two birth cohorts (German Infant Nutritional Intervention Study (GINI) and Influence of Life-style factors on the development of the Immune System and Allergies in East and West Germany (LISA)) in the Munich metropolitan area. Associations between air pollution concentrations at birth address and 1-year and 2-year incidences of respiratory symptoms were analysed. RESULTS: The following means for the estimated exposures to PM2.5, PM2.5 absorbance and NO2 were obtained: 12.8 microg/m3, 1.7x10(-5) m(-1) and 35.3 mug/m3, respectively. Adjusted odds ratios (ORs) for wheezing, cough without infection, dry cough at night, bronchial asthma, bronchitis and respiratory infections indicated positive associations with traffic-related air pollutants. After controlling for individual confounders, significant associations were found between the pollutant PM2.5 and sneezing, runny/stuffed nose during the first year of life (OR 1.16, 95% confidence interval 1.01 to 1.34) Similar effects were observed for the second year of life. These findings are similar to those from our previous analysis that were restricted to a subcohort in Munich city. The extended study also showed significant effects for sneezing, running/stuffed nose. Additionally, significant associations were found between NO2 and dry cough at night (or bronchitis) during the first year of life. The variable "living close to major roads" (<50 m), which was not analysed for the previous inner city cohort with birth addresses in the city of Munich, turned out to increase the risk of wheezing and asthmatic/spastic/obstructive bronchitis. CONCLUSIONS: Effects on asthma and hay fever are subject to confirmation at older ages, when these outcomes can be more validly assessed.

Air Pollutants↗
PubMed2000

Exposure of Paris taxi drivers to automobile air pollutants within their vehicles.

OBJECTIVES: To study the exposure of Parisian taxi drivers to automobile air pollutants during their professional activity. METHODS: A cross sectional study was carried out from 27 January to 27 March 1997, with measurements performed in the vehicles of 29 randomly selected drivers. Carbon monoxide (CO) content was measured over an 8 hour period by a CO portable monitor. The fine suspended particles were measured according to the black smoke index (BS), with a flow controlled portable pump provided with a cellulose filter. The nitrogen oxides, NO and NO(2) were measured with a passive sampler. RESULTS: These drivers are exposed during their professional activity to relatively high concentrations of pollutants (mean, median (SD) 3.8, 2 (1.7) ppm for CO, 168, 164 (53) micrograms/m(3) for BS, 625, 598 (224) micrograms/m(3) for NO, and 139, 131 (43) micrograms/m(3) for NO(2).) For CO the concentrations were clearly lower than the threshold values recommended by the World Health Organisation. The situation is less satisfactory for the other pollutants, especially for the BS index. All concentrations of pollutants recorded were noticeably higher than concentrations in air recorded by the ambient Parisian air monitoring network and were close to, or slightly exceeded, the concentrations measured at the fixed stations close to automobile traffic. Pollutant concentrations were also influenced greatly by weather conditions. CONCLUSION: This first French study conducted in taxi drivers shows that they are highly exposed to automobile pollutants. The results would justify a medical follow up of this occupational group.

Air Pollutants, Occupational↗
PubMed2003

Effects of bioaerosol polluted outdoor air on airways of residents: a cross sectional study.

BACKGROUND: Bioaerosol pollution of workplace and home environments mainly affects airways and mucous membranes. The effect of environmental outdoor residential bioaerosol pollution, for example, livestock holdings, farming, and waste disposal plants, is unclear. AIMS: To investigate the perceived health of residents living in areas with measurable outdoor bioaerosol pollution (for example, spores of Aspergillus fumigatus and actinomycetes), and effects of accompanying odours. METHODS: In a cross sectional study, double blinded to ongoing microbial measurements, doctors collected 356 questionnaires from residents near a large scale composting site, and from unexposed controls in 1997. Self reported prevalence of health complaints during the past year, doctors' diagnoses, as well as residential odour annoyance were assessed. Microbiological pollution was measured simultaneously in residential outdoor air. RESULTS: Concentrations of >10(5) colony forming units of thermophilic actinomycetes, moulds, and total bacteria/m(3) air were measured 200 m from the site, dropping to near background concentrations within 300 m. Positive adjusted associations were observed for residency within 150-200 m from the site versus unexposed controls for self reported health complaints: "waking up due to coughing", odds ratio (OR) 6.59 (95% confidence interval (CI) 2.57 to 17.73); "coughing on rising or during the day", OR 3.18 (95% CI 1.24 to 8.36); "bronchitis", OR 3.59 (95% CI 1.40 to 9.4); and "excessive tiredness", OR 4.27 (95% CI 1.56 to 12.15). Reports of irritative airway complaints were associated with residency in the highest bioaerosol exposure, 150-200 m (versus residency >400-500 m) from the site, and period of residency more than five years, but not residential odour annoyance. Lifetime prevalence of self reported diseases did not differ with exposure. CONCLUSIONS: Bioaerosol pollution of residential outdoor air can occur in concentrations found in occupational environments. For the first time residents exposed to bioaerosol pollution were shown to report irritative respiratory complaints similar to mucous membrane irritation independently of perceived odours.

Aerosols↗
PubMed2006

Association between air pollution and general practitioner visits for respiratory diseases in Hong Kong.

BACKGROUND: Few studies have explored the relation between air pollution and general practitioner (GP) consultations in Asia. Clinic attendance data from a network of GPs were studied, and the relationship between daily GP consultations for upper respiratory tract infections (URTI) and non-URTI respiratory diseases and daily air pollutant concentrations measured in their respective districts was examined. METHODS: A time series study was performed in 2000-2002 using data on daily patient consultations in 13 GP clinics distributed over eight districts. A Poisson regression model was constructed using the generalised additive model approach for each GP clinic, and associations with daily numbers of first visits for URTI were sought for daily concentrations of the following air pollutants: SO(2), NO(2), O(3), PM(10,) and PM(2.5). A summary relative risk of first visits to the GP for URTI per unit increase in concentration for each air pollutant was derived using a random effect model. First visits for non-URTI respiratory diseases were analysed in three GP clinics. RESULTS: Significant associations were observed between first visits for URTI and an increase in the concentrations of NO(2), O(3), PM(10), and PM(2.5). The excess risk was highest for NO(2) (3.0%), followed by O(3) (2.5%), PM(2.5) (2.1%), and PM(10) (2.0%). Similar associations with these air pollutants were found for non-URTI respiratory diseases. CONCLUSIONS: These results provide further evidence that air pollution contributes to GP visits for URTI and non-URTI respiratory diseases in the community.

Air Pollution↗