Sulfur Dioxide Air Pollution in New York City: Statistical Analysis of Twelve Years

During the heating season SO₂ levels at three stations in New York City exhibit irregular hourly and daily variation about a long-term repeating annual sine wave which peaks in mid-January. This sine wave varies slightly in phase from station to station, but is nearly coincident in time with long term Normal Temperature observed at Central Park. During summer, SO₂ levels at these stations remain relatively constant at their lowest values. On a daily basis, SO₂ levels tend to exhibit a characteristic bimodality during the heating season. The paper concludes with suggestions for further analysis. Mathematical convenience suggests defining “pollution winter” and ”pollution summer” in agreement with the high and low regions of the sine wave. The frequency distribution for the pollution winter lies considerably above, and that for pollution summer lies considerably below the twelve year distribution for all seasons combined     

环境空气质量自动监测站的管理与维护

随着工业化、城镇化的深入推进,二氧化硫、氮氧化物、烟粉尘和挥发性有机物等各类污染物排放到环境中,致使中国大气受到严重污染,给人体的健康、动植物的生长、发育和繁殖等带来负面的影响。为实时监测环境空气质量,建立环境空气质量自动监测站逐渐成为大气污染防治的主要手段。文中以环境空气质量自动监测站为研究对象,提出环境空气质量自动监测站管理与维护面临的问题,探讨相应的解决措施,以期为环境空气质量自动监测站的管理与维护提供参考依据。     

The Characterization of Ozone,Sulfur Dioxide,and Nitrogen Dioxide for Selected Monitoring Sites in the Federal Republic of Germany

Ambient ozone, sulfur dioxide, and nitrogen dioxide data collected at 11 rural gaseous air pollution monitoring stations located throughout the Federal Republic of Germany (FRG) were characterized to provide a basis for investigating the effect these air pollutants may have on forest decline. For any given year, with the exception of the Waldhof site, the ozone monitoring sites did not experience more than 50 occurrences of hourly mean concentrations equal to or above 0.10 ppm. In most cases, the number of occurrences equal to or above 0.10 ppm at the FRG ozone monitoring sites was below the number experienced at a rural forested site located at Whiteface Mountain, New York. Several of the FRG monitoring sites experienced a large number of occurrences of hourly mean ozone concentrations between 0.08 and 0.10 ppm. Hof, Selb, Arzberg, and Waldhof experienced several occurrences of elevated levels of sulfur dioxide concentrations. The nitrogen dioxide 24-h mean concentrations were low for all sites. Because the 24-h mean data may mask the occurrence of a few high concentration events, it is not known if any of the sites that monitored nitrogen dioxide experienced short-term elevated concentrations. To gain further insight into the possible effect of pollutant mixtures on vegetation, future efforts should involve characterizing the timing of multi-pollutant exposures.     

Injury by Sulfur Dioxide,Hydrogen Fluoride,and Chlorine As Observed and Reflected On Vegetation in the Field

Plants were examined at three different locations in the eastern part of the United States to determine whether damage from air pollution had occurred. This paper discusses sulfur dioxide damage in the metropolitan New York City area; hydrogen fluoride damage near a glass fiber manufacturing plant in the midwest; and hydrochloric acid mist and chlorine damage from a manufacturing operation in an eastern state. The symptoms that developed in vegetation were often found to be similar. Chemical and microscopical analyses were helpful in diagnosing the toxicants.     

Air Quality Impact of Aircraft at Ten U.S. Air Force Bases

Data on visits to New York City metropolitan area hospital emergency rooms for asthmatic attacks were analyzed to identify asthma “events”: days when the number of such visits was unusually high. In the fall season such days tended to occur simultaneously at all hospitals of the study, and thus can be plausibly associated with some environmental agent acting simultaneously throughout the city. Data on sulfur dioxide and particulate concentrations from the 40-station New York City Aerometric Network were used as pollution measures, and a search for a relationship between asthma “events” and air pollution levels on the same day and on the preceding day was made using standard statistical techniques. No relationship was found.     

A study of air pollutants and acute asthma exacerbations in urban areas: status report

A study to try to better understand the interactions between various air contaminants and acute asthma exacerbations is described. The study evaluates temporal associations between a panel of air contaminants and acute asthmatic exacerbations as measured by emergency room visits for asthma in communities in the Bronx and Manhattan in New York City (NYC). In addition, ambient levels of various air pollutants in two NYC communities are being compared. Almost 2 years of daily data have been collected for most of the air contaminants to be investigated. The air contaminants measured include gaseous compounds (ozone, sulfur dioxide, nitrogen oxides, aldehydes, nitrous acid, nitric acid, hydrochloric acid and ammonia), particulate matter components (metals, elemental and organic carbon, sulfate, hydrogen ion, pollen, mold spores and particle mass and number).     

An Air Pollution Incident Due to a Stationary Front

In January 1971, the New York City area experienced a period of high pollution in which concentrations exceeded the present criteria for Stage I of the New York City Alert-Warning System. The incident was unusual because the high concentrations were associated with a weak frontal system which moved back and forth over the area and not with a stagnating anticyclone. Concentrations of pollutants were found to be closely related to the movement of the frontal system as well as to changes in wind speed and stability. Climatological criteria for identifying-periods of potential high air pollution and the criteria for mixing heights, transport wind speed and ventilation factors necessary for the issuance of an official advisory from the National Meteorological Center were not met during this incident. Therefore, some re-evaluation and redefinition of these criteria are recommended.     

Development of Criteria for Siting Air Monitoring Stations

A critical problem arises if one attempts to compare data from air monitoring stations in different cities, because there are so many differences in monitoring site locations. Some air monitoring stations are on the 6 th and 8 th floors of tall buildings in downtown areas; some are at ground level beside streets with heavy traffic; some are in residential areas with little traffic or industry; and some are in suburban or nonurban areas. Unfortunately, there is ample evidence that the location of a monitoring station relative to nearby sources (such as highways) affects the values observed at the station, particularly for carbon monoxide and other vehicular pollutants. Thus, a standardized system of site selection, such as the one proposed here, appears essential to improve the comparability and meaningfulness of data obtained from different air monitoring stations throughout the Nation.     

Assessment of ambient air quality in the port of Naples

Two experimental monitoring campaigns were carried out in 2012 to investigate the air quality in the port of Naples, the most important in southern Italy for traffic of passengers and one of the most important for goods. Therefore, it represents an important air pollution source located close to the city of Naples. The concentrations of sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and BTEX (benzene, toluene, ethylbenzene, and xylenes) in the air were measured at 15 points inside the Naples port area through the use of passive samplers. In addition, a mobile laboratory was positioned in a fixed point inside the port area to measure continuous concentration of pollutants together with particulate matter, ambient parameters, and wind direction and intensity. The pollution levels monitored were compared with those observed in the urban area of Naples and in other Mediterranean ports. Even though the observation time was limited, measured concentrations were also compared with limit values established by European legislation. All the measured pollutants were below the limits with the exception of nitrogen dioxide: its average concentration during the exposition time exceeded the yearly limit value. A spatial analysis of data, according to the measured wind direction and intensity, provided information about the effects that ship emissions have on ambient air quality in the port area. The main evidence indicates that ship emissions influence sulfur dioxide concentration more than any other pollutants analyzed.

Implications: Two monitoring campaigns were carried out to measure BTEX, SO₂, NO₂, and PM₁₀ (particulate matter with an aerodynamic diameter <10 μm) air concentrations in the port of Naples. NO₂ hourly average and PM₁₀ daily average comply with European legislative standards. Spatial variation of pollutants long the axis corresponding to the prevailing wind direction seems to indicate a certain influence of ship emissions for SO₂. For NO₂ and PM₁₀, a correlation between concentrations in the harbor and those measured by the air quality monitoring stations sited in the urban area of Naples was observed, indicating a possible contribution of the near road traffic to the air pollution in the port of Naples.     

Seasonal variation of air pollution index: Hong Kong case study

Air pollution is an important and popular topic in Hong Kong as concerns have been raised about the health impacts caused by vehicle exhausts in recent years. In Hong Kong, sulphur dioxide SO2, nitrogen dioxide (NO2), nitric oxide (NO), carbon monoxide (CO), and respirable suspended particulates (RSP) are major air pollutants caused by the dominant usage of diesel fuel by goods vehicles and buses. These major pollutants and the related secondary pollutant, e.g., ozone (O3), become and impose harmful impact on human health in Hong Kong area after the northern shifting of major industries to Mainland China. The air pollution index (API), a referential parameter describing air pollution levels, provides information to enhance the public awareness of air pollutions in time series since 1995. In this study, the varying trends of API and the levels of related air pollutants are analyzed based on the database monitored at a selected roadside air quality monitoring station, i.e., Causeway Bay, during 1999-2003. Firstly, the original measured pollutant data and the resultant APIs are analyzed statistically in different time series including daily, monthly, seasonal patterns. It is found that the daily mean APIs in seasonal period can be regarded as stationary time series. Secondly, the auto-regressive moving average (ARMA) method, implemented by Box-Jenkins model, is used to forecast the API time series in different seasonal specifications. The performance evaluations of the adopted models are also carried out and discussed according to Bayesian information criteria (BIC) and root mean square error (RMSE). The results indicate that the ARMA model can provide reliable, satisfactory predictions for the problem interested and is expecting to be an alternative tool for practical assessment and justification.     

Ambient Air Pollution and Daily Pediatric Hospitalizations for Asthma (5 pp)

Background, Aim and Scope A series of severe air pollution episodes in Europe and North America prior to 1960 have focused scientific and regulatory attention on the adverse effects of air pollution on human health. As a consequence of significant reductions in ambient air pollution levels in the intervening years, scientists and public health officials have become more concerned with the potential health effects of exposure to routine concentrations of air pollution. Several recent time series studies conducted world-wide have found relatively low levels of air pollutants that are below national standards were associated with adverse effects on mortality and morbidity. This study examined the effects of ambient air pollution indicators on the daily rate of pediatric hospital admissions for asthma in the Oklahoma City Metropolitan area from 2001-2003. Results: Negative binomial regression analysis revealed significant relationships between the total number of hospitalizations per day and the one-hour maximum NO2 level, the proportion of susceptible children < 5 years old, and the ratio of temperature to humidity. Discussion: This study of the total number of children aged ≤ 14 years old experiencing hospitalizations on a daily basis in the Oklahoma City area from 2001-2003 underscores factors other than ambient air pollution, especially when concentrations are low, affect hospitalizations for pediatric asthma. For example, information related to indoor air quality, health care, family history, and exposure to environmental tobacco smoke and other irritants are not obtainable. Yet, those factors are risk drivers for asthma. Similarly, health privacy requirements prevented obtaining data on physiological factors specific to each child such as differentials in airways functional capacity or other impairments influenced asthma exacerbation. This makes calculating relative risk inappropriate. Conclusions: Although ambient air pollution concentrations and meteorological conditions influence pediatric asthma hospitalizations, they are not the major predictors in the Oklahoma City metropolitan area. This is consistent with other research that finds limited effects associated with low levels for concentrations of the criteria pollutants.     

Modeling traffic air pollution in street canyons in New York City for intra-urban exposure assessment in the US Multi-Ethnic Study of atherosclerosis and air pollution

We evaluated the Danish AirGIS air quality and exposure model system using air quality measurement data from New York City in the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Measurements were used from three US EPA Air Quality System (AQS) monitoring stations and a comprehensive MESA Air measurement campaign including about 150 different locations and about 650 samples of about 2 week measurements of NO_x, NO₂ and PM_2.5. AirGIS is a deterministic exposure model system based on the dispersion models Operational Street Pollution Model (OSPM) and the Urban Background Model (UBM). The UBM model reproduced the annual levels within 1–26% depending on station and pollutant at the three urban background EPA monitor stations, and generally reproduced well the seasonal and diurnal variation. The full model with OSPM and UBM reproduced the MESA Air measurements with a correlation coefficient of r² = 0.51 for NO_x, r² = 0.28 for NO₂ and r² = 0.73 for PM_2.5.     

An Advective Model for Predicting Air Pollution within an Urban Heat Island With Applications to New York City

A simple air pollution model has been tested for New York City with data from five mornings which were characterized by urban heat island effects. The model is nondiffusive and relies primarily upon conservation of mass. The correlation coefficient between over 400 predicted and observed values of SO₂ mixing ratio was 0.83.     

Another Look at New York City’s Air Pollution Problem

An analysis of the ambient air quality in New York City over the past several years has been made. The various sources of the contaminants are identified and evaluated as to their effects on ambient air quality. Meteorological data have been analyzed to develop insight into the influence of weather conditions upon ground level pollution concentrations. The results of these analyses are employed to indicate the approaches that will be most effective in improving air quality.     

Statistical Analysis of Trends in Urban Ozone Air Quality

The purpose of this paper is to demonstrate the use of some statistical methods for examining trends in ambient ozone air quality downwind of major urban areas. To this end, daily maximum 1 -hr ozone concentrations measured over New Jersey, metropolitan New York City and Connecticut for the period 1980 to 1989 were assembled and analyzed. This paper discusses the application of the bootstrap method, extreme value statistics and a nonparametric test for evaluating trends in urban ozone air quality. The results indicate that although there is an improvement in ozone air quality downwind of New York City, there has been little change in ozone levels upwind of New York City during this ten-year period.     

Prediction of carbon monoxide acute air pollution episodes. Model formulation and first application in Lombardy

This paper describes a method to forecast the exceedance probability of a fixed threshold for a certain air pollutant concentration. This general approach has been applied in the case of carbon monoxide on 35 traffic monitoring stations in the Lombardy Region. The implemented model has been called FOREPOLL (Forecast Pollution).The model structure, consisting in three basic modules (the deterministic, the stochastic and the Bayesian one), has been thought to be adjustable to different stations of an air quality network and to various pollutants. Forepoll uses the last biennium data set of the station in exam (pollutants and micrometeorological parameters) as a moving learning time and also needs the forecasted synoptic weather type. In the first module the daily maxima of the hourly measured pollutant concentrations are checked in order to eliminate some known physical dependencies, such as the temperature dependence of the emissions. Then the data are divided into subgroups depending on the weather type and in each group fitted by a different Weibull distribution. To provide a first a priori exceedance probability, this distribution is daily rebuilt by taking into account the forecasted parameters. In the last module this probability is enhanced or reduced using simple, experience based, bayesian rules providing the a posteriori exceedance probability.Model validation trials have been carried out on a year of CO forecasted concentrations in different air quality stations; the first results are quite good particularly for the metropolitan areas, because the model seems to work better in case of stronger and more diffuse pollution.     

Spatial variation of airborne pollutant concentrations in Brisbane,Australia and its potential impact on population exposure assessment

Spread of air pollution sources and non-uniform mixing conditions in urban or regional air sheds often result in spatial variation of pollutant concentrations over different parts of the air sheds. A comprehensive understanding of this variation of concentrations is imperative for informed planning, monitoring and assessment in a range of critical areas including assessment of monitoring network efficiency or assessment of population exposure variation as a function of the location in the city. The aims of this work were to study the citywide variability of pollutants as measured by “urban background” type monitoring stations and to interpret the results in relation to the applicability of the data to population exposure assessments and the network efficiency. A comparison between ambient concentrations of NO_x, ozone and PM₁₀ was made for three stations in the Brisbane air shed network. The best correlated between the three stations were ozone concentrations followed by NO_x concentration, with the worst correlations observed for PM₁₀. With a few exceptions correlations of all pollutants between the stations were statistically significant. Marginally better were the correlations for the lower concentrations of pollutants that represent urban background, over the correlations for higher concentrations, representing peak values. Implications of these findings on application of the monitoring data to air-quality management, as well as the need for further investigations has been discussed.     

Air quality mapping using GIS and economic evaluation of health impact for Mumbai City,India

Mumbai, a highly populated city in India, has been selected for air quality mapping and assessment of health impact using monitored air quality data. Air quality monitoring networks in Mumbai are operated by National Environment Engineering Research Institute (NEERI), Maharashtra Pollution Control Board (MPCB), and Brihanmumbai Municipal Corporation (BMC). A monitoring station represents air quality at a particular location, while we need spatial variation for air quality management. Here, air quality monitored data of NEERI and BMC were spatially interpolated using various inbuilt interpolation techniques of ArcGIS. Inverse distance weighting (IDW), Kriging (spherical and Gaussian), and spline techniques have been applied for spatial interpolation for this study. The interpolated results of air pollutants sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and suspended particulate matter (SPM) were compared with air quality data of MPCB in the same region. Comparison of results showed good agreement for predicted values using IDW and Kriging with observed data. Subsequently, health impact assessment of a ward was carried out based on total population of the ward and air quality monitored data within the ward. Finally, health cost within a ward was estimated on the basis of exposed population. This study helps to estimate the valuation of health damage due to air pollution.

Implications: Operating more air quality monitoring stations for measurement of air quality is highly resource intensive in terms of time and cost. The appropriate spatial interpolation techniques can be used to estimate concentration where air quality monitoring stations are not available. Further, health impact assessment for the population of the city and estimation of economic cost of health damage due to ambient air quality can help to make rational control strategies for environmental management. The total health cost for Mumbai city for the year 2012, with a population of 12.4 million, was estimated as USD8000 million.