A Regujatory Framework for Setting Air Emission Limits for Noncriteria Pollutants

The information presented in this paper is concerned with the effects of ambient ozone on crop yield reduction and the resultant economic losses. Yield data for nine crops within the South Coast Air Basin (SCAB) of California were obtained for the 12-year period, 1964 through 1975. Ozone concentrations, temperature, precipitation, and relative humidity data were related to the yields by using regression models. Estimated yield reductions due to ozone for 1975, varied from zero to 57% depending on crop and location. Economic welfare losses calculated from the yield reductions were $57.3 and $45.7 million for producer’s and consumer’s surplus, respectively. The total loss from ozone to agriculture related economic sectors determined by input-output analysis was $276 million in the SCAB and $36.6 million in the remainder of the state.     

Economic Assessment of the Effects of Air Pollution on Agricultural Crops in the San Joaquin Valley

Physical and economic impacts of 1978 ambient levels of ozone and sulfur dioxide on 33 crops In the San Joaquin Valley are estimated. The field data regression approach Is used and evaluated for estimating yield losses. The effects of alternative air pollution measures and regression functional forms are evaluated. An economic model is employed that accounts for both farm and market responses to yield improvements from reduced air pollution. Economic damages were estimated to exceed $100 million in 1978 with the biggest losers being the producers of cotton and producers and consumers of grapes, a crop that has heretofore been Ignored in agricultural assessments of pollution damage.     

Ambient Oxidant Exposure andHealth Costs in the United States—1973

The body of information presented in this paper is directed to policy makers and administrators involved in the evaluation and assessment of damages caused by oxidant air pollution on human health and welfare and of possible benefits of control.

To provide a comparison of some of the benefits that can be obtained by reducing photochemical oxidant levels, estimated health costs were derived from data relating adverse health effects to hourly oxidant concentrations. Hourly oxidant or ozone concentrations were measured at approximately 400 monitoring stations scattered throughout the U.S. Most of these sites were located in major urban areas or in other areas where high oxidant concentrations prevailed. Estimates of populations at risk and per capita health costs were generated for those areas where oxidant data was available.

During the period 1971-1973, nearly two-thirds of the U.S. population resided in areas where the hourly primary standard for oxidants of 160 µg/m³ was exceeded. The total annual health cost attributable to oxidants was estimated to range from $120 to over $240 million in the U.S.     

Estimated crop yield losses due to surface ozone exposure and economic damage in India

In this study, we estimate yield losses and economic damage of two major crops (winter wheat and rabi rice) due to surface ozone (O₃) exposure using hourly O₃ concentrations for the period 2002–2007 in India. This study estimates crop yield losses according to two indices of O₃ exposure: 7-h seasonal daytime (0900–1600 hours) mean measured O₃ concentration (M7) and AOT40 (accumulation exposure of O₃ concentration over a threshold of 40 parts per billion by volume during daylight hours (0700–1800 hours), established by field studies. Our results indicate that relative yield loss from 5 to 11 % (6–30 %) for winter wheat and 3–6 % (9–16 %) for rabi rice using M7 (AOT40) index of the mean total winter wheat 81 million metric tons (Mt) and rabi rice 12 Mt production per year for the period 2002–2007. The estimated mean crop production loss (CPL) for winter wheat are from 9 to 29 Mt, account for economic cost loss was from 1,222 to 4,091 million US$ annually. Similarly, the mean CPL for rabi rice are from 0.64 to 2.1 Mt, worth 86–276 million US$. Our calculated winter wheat and rabi rice losses agree well with previous results, providing the further evidence that large crop yield losses occurring in India due to current O₃ concentration and further elevated O₃ concentration in future may pose threat to food security.     

Loss of crop yields in India due to surface ozone: an estimation based on a network of observations

Surface ozone is mainly produced by photochemical reactions involving various anthropogenic pollutants, whose emissions are increasing rapidly in India due to fast-growing anthropogenic activities. This study estimates the losses of wheat and rice crop yields using surface ozone observations from a group of 17 sites, for the first time, covering different parts of India. We used the mean ozone for 7 h during the day (M7) and accumulated ozone over a threshold of 40 ppbv (AOT40) metrics for the calculation of crop losses for the northern, eastern, western and southern regions of India. Our estimates show the highest annual loss of wheat (about 9 million ton) in the northern India, one of the most polluted regions in India, and that of rice (about 2.6 million ton) in the eastern region. The total all India annual loss of 4.0–14.2 million ton (4.2–15.0%) for wheat and 0.3–6.7 million ton (0.3–6.3%) for rice are estimated. The results show lower crop loss for rice than that of wheat mainly due to lower surface ozone levels during the cropping season after the Indian summer monsoon. These estimates based on a network of observation sites show lower losses than earlier estimates based on limited observations and much lower losses compared to global model estimates. However, these losses are slightly higher compared to a regional model estimate. Further, the results show large differences in the loss rates of both the two crops using the M7 and AOT40 metrics. This study also confirms that AOT40 cannot be fit with a linear relation over the Indian region and suggests for the need of new metrics that are based on factors suitable for this region.     

The global impact of ozone on agricultural crop yields under current and future air quality legislation

In this paper we evaluate the global impact of surface ozone on four types of agricultural crop. The study is based on modelled global hourly ozone fields for the year 2000 and 2030, using the global 1°×1° 2-way nested atmospheric chemical transport model (TM5). Projections for the year 2030 are based on the relatively optimistic “current legislation (CLE) scenario”, i.e. assuming that currently approved air quality legislation will be fully implemented by the year 2030, without a further development of new abatement policies. For both runs, the relative yield loss due to ozone damage is evaluated based on two different indices (accumulated concentration above a 40 ppbV threshold and seasonal mean daytime ozone concentration respectively) on a global, regional and national scale. The cumulative metric appears to be far less robust than the seasonal mean, while the seasonal mean shows satisfactory agreement with measurements in Europe, the US, China and Southern India and South-East Asia.Present day global relative yield losses are estimated to range between 7% and 12% for wheat, between 6% and 16% for soybean, between 3% and 4% for rice, and between 3% and 5% for maize (range resulting from different metrics used). Taking into account possible biases in our assessment, introduced through the global application of “western” crop exposure–response functions, and through model performance in reproducing ozone-exposure metrics, our estimates may be considered as being conservative.Under the 2030 CLE scenario, the global situation is expected to deteriorate mainly for wheat (additional 2–6% loss globally) and rice (additional 1–2% loss globally). India, for which no mitigation measures have been assumed by 2030, accounts for 50% of these global increase in crop yield loss. On a regional-scale, significant reductions in crop losses by CLE-2030 are only predicted in Europe (soybean) and China (wheat).Translating these assumed yield losses into total global economic damage for the four crops considered, using world market prices for the year 2000, we estimate an economic loss in the range $14–$26 billion. About 40% of this damage is occurring in China and India. Considering the recent upward trends in food prices, the ozone-induced damage to crops is expected to offset a significant portion of the GDP growth rate, especially in countries with an economy based on agricultural production.     

Improved Ventilation of Open Top Greenhouses

Plant injury caused by air pollutants is a well recognized effect causing economic losses totalling millions of dollars. Farm crops, forest species, and ornamentals are all affected depending upon kind of plant and degree of exposure. Benedict¹ estimated the minimum annual agricultural losses in the U. S. to be $132 million in 1969-1971. Millecan² estimated California crop losses caused by air pollutants to be at least $25 million in 1972. Recent studies by Brewer³ in which conventional greenhouses were placed in the field over cotton gave results showing yields were reduced by 10-30% in the San Joaquin valley where significant levels of photochemical smog occur. However, these estimates of losses represent little more than educated guesses because the procedures available for obtaining the information are so imprecise.     

Sulfur Dioxide and Material Damage

Whereas most estimates of material damage are based on industrial surveys, the estimates produced in this study were derived from material damage experiments and ambient air quality data. Air quality data on SO₂ were obtained from 200 or more monitoring sites primarily located in heavily populated or polluted areas. Material threshold damage function data were then compared with SO₂ levels, and an estimate of losses, as reflected in increased maintenance and replacement costs, was determined. Estimates of the total stock of various materials in use were derived from census and industry data and allocated geographically according to population. A substantial decrease in the ambient SO₂ levels, particularly in larger urban areas, has occurred during the past five years. From 1968 to 1972, the estimated amount of material damage from SO₂ in the U. S. decreased from $900 million/yr to less than $100 million. During this period, the estimated percentage of man made materials exposed to SO₂ levels exceeding the proposed secondary annual average standard (60 μg/m³) and primary annual average standard (80 μg/m³) in the U. S. fell respectively, from 20% to less than 5% and from more than 10% to less than 1%. Most of the present loss is attributed to corrosion damage of metallic surfaces that are normally exposed to the ambient environment.     

An investigation of widespread ozone damage to the soybean crop in the upper Midwest determined from ground-based and satellite measurements

Elevated concentrations of ground-level ozone (O₃) are frequently measured over farmland regions in many parts of the world. While numerous experimental studies show that O₃ can significantly decrease crop productivity, independent verifications of yield losses at current ambient O₃ concentrations in rural locations are sparse. In this study, soybean crop yield data during a 5-year period over the Midwest of the United States were combined with ground and satellite O₃ measurements to provide evidence that yield losses on the order of 10% could be estimated through the use of a multiple linear regression model. Yield loss trends based on both conventional ground-based instrumentation and satellite-derived tropospheric O₃ measurements were statistically significant and were consistent with results obtained from open-top chamber experiments and an open-air experimental facility (SoyFACE, Soybean Free Air Concentration Enrichment) in central Illinois. Our analysis suggests that such losses are a relatively new phenomenon due to the increase in background tropospheric O₃ levels over recent decades. Extrapolation of these findings supports previous studies that estimate the global economic loss to the farming community of more than $10 billion annually.     

Crop loss assessment for California: modeling losses with different ozone standard scenarios

Crop yield losses were estimated for ambient O3 concentrations and for a series of potential O3 air quality standards for California, including the current statewide 1-h oxidant (O3) standard of 0.10 ppm (196 microg m(-3)), 12-h growing season averages, and other models. A model for statewide losses was developed using hourly O3 data for all sites in the State, county crop productivity data, and available O3 concentration-yield loss equations to determine potential yield losses for each crop in each county in California for 1984. Losses were based on comparison to an estimated background filtered air concentration of 0.025 or 0.027 ppm, for 12 or 7 h, respectively. Potential losses due to ambient air in 1984 were estimated at 19% to 25% for dry beans, cotton, grapes, lemons, onions, and oranges. Losses of 5% to 9% were estimated for alfalfa and sweet corn. Losses of 4% or less were estimated for barley, field corn, lettuce, grain sorghum, rice, corn silage, spinach, strawberries, sugar beets, fresh tomatoes, processing tomatoes, and wheat. Implementation of either a modified rollback to meet the current 1 h California O3 standard (0.10 ppm) or a three-month, 12-h growing season average of 0.045 ppm was necessary to produce large reductions in potential crop losses.     

An ex post cost-benefit analysis of the nitrogen dioxide air pollution control program in Tokyo

The benefits and costs of past nitrogen dioxide (NO2) control policies were calculated for Tokyo, Japan, using environmental, economic, political, demographic, and medical data from 1973 to 1994. The benefits of NO2 control were estimated as medical expenses and lost work time due to hypothetical no-control air concentrations of NO2. Direct costs were calculated as annualized capital expenditures and 1 year's operating costs for regulated industries plus governmental agency expenses. The major findings were as follows: (1) Using Tokyo's average medical cost of pollution-related illness, the best net estimate of the avoided medical costs due to incidence of phlegm and sputum in adults was 730 billion yen ($6.08 billion; 1 U.S. dollar = 120 yen). (2) The best net estimate of the avoided medical costs due to incidence of lower respiratory illness in children was 93 billion yen ($775 million). (3) Using Tokyo's average duration of pollution-related illness and average wages, the best net estimate of the avoided costs of lost wages in workers was 760 billion yen ($6.33 billion). (4) The best net estimate of the avoided costs of lost wages in mothers caring for their sick children was 100 billion yen ($833 million). (5) Using Tokyo-specific data, the best net costs were estimated as 280 billion yen ($2.33 billion). (6) Using human health and productivity benefits, and annualized capital cost and operating cost estimates, the best net benefits-to-costs ratio was 6:1 (upper limit 44:1; lower limit 0.3:1). Benefit calculations were sensitive to assumptions of mobile source emissions and certain health impacts that were not included. Cost calculations were highly dependent on assumptions of flue gas volume and fuel use. For comparative purposes, we identified other studies for air pollution-related illness. Assumptions that formed the basis for most of the inputs in the present study, such as duration of illness, medical treatment costs, per person illness in children, and lost wages for working mothers, were similar to those recommended in the literature. Lost wages in sick workers and per capita illness incidence in adults were higher than numbers reported elsewhere. Further advances in cost-benefit analysis (CBA) procedures to evaluate the economic effectiveness of NO2 controls in Tokyo are recommended to estimate impacts and values for additional human health benefits, ecosystem health and productivity effects, and nonliving system effects, as well as benefits of ancillary reductions in other pollutants. The present study suggests that Tokyo's past NO2 control policies in total were economically quite effective.     

Comparison of models used for national agricultural ammonia emission inventories in Europe: Litter-based manure systems

Six N-flow models, used to calculate national ammonia (NH₃) emissions from agriculture in different European countries, were compared using standard data sets. Scenarios for litter-based systems were run separately for beef cattle and for broilers, with three different levels of model standardisation: (a) standardized inputs to all models (FF scenario); (b) standard N excretion, but national values for emission factors (EFs) (FN scenario); (c) national values for N excretion and EFs (NN scenario). Results of the FF scenario for beef cattle produced very similar estimates of total losses of total ammoniacal-N (TAN) (±6% of the mean total), but large differences in NH₃ emissions (±24% of the mean). These differences arose from the different approaches to TAN immobilization in litter, other N losses and mineralization in the models. As a result of those differences estimates of TAN available at spreading differed by a factor of almost 3. Results of the FF scenario for broilers produced a range of estimates of total changes in TAN (±9% of the mean total), and larger differences in the estimate of NH₃ emissions (±17% of the mean). The different approaches among the models to TAN immobilization, other N losses and mineralization, produced estimates of TAN available at spreading which differed by a factor of almost 1.7. The differences in estimates of NH₃ emissions decreased as estimates of immobilization and other N losses increased. Since immobilization and denitrification depend also on the C:N ratio in manure, there would be advantages to include C flows in mass-flow models. This would also provide an integrated model for the estimation of emissions of methane, non-methane VOCs and carbon dioxide. Estimation of these would also enable an estimate of mass loss, calculation of the N and TAN concentrations in litter-based manures and further validation of model outputs.     

An Ex Post Cost-Benefit Analysis of the Nitrogen Dioxide Air Pollution Control Program in Tokyo

ABSTRACT

The benefits and costs of past nitrogen dioxide (NO₂) control policies were calculated for Tokyo, Japan, using environmental, economic, political, demographic, and medical data from 1973 to 1994. The benefits of NO₂ control were estimated as medical expenses and lost work time due to hypothetical no-control air concentrations of NO₂. Direct costs were calculated as annualized capital expenditures and 1 year's operating costs for regulated industries plus governmental agency expenses. The major findings were as follows:

(1) Using Tokyo's average medical cost of pollution-related illness, the best net estimate of the avoided medical costs due to incidence of phlegm and sputum in adults was 730 billion yen ($6.08 billion; 1 U.S. dollar = 120 yen).

(2) The best net estimate of the avoided medical costs due to incidence of lower respiratory illness in children was 93 billion yen ($775 million).

(3) Using Tokyo's average duration of pollution-related illness and average wages, the best net estimate of the avoided costs of lost wages in workers was 760 billion yen ($6.33 billion).

(4) The best net estimate of the avoided costs of lost wages in mothers caring for their sick children was 100 billion yen ($833 million).

(5) Using Tokyo-specific data, the best net costs were estimated as 280 billion yen ($2.33 billion).

(6) Using human health and productivity benefits, and annualized capital cost and operating cost estimates, the best net benefits-to-costs ratio was 6:1 (upper limit 44:1; lower limit 0.3:1). Benefit calculations were sensitive to assumptions of mobile source emissions and certain health impacts that were not included. Cost calculations were highly dependent on assumptions of flue gas volume and fuel use. For comparative purposes, we identified other studies for air pollution-related illness. Assumptions that formed the basis for most of the inputs in the present study, such as duration of illness, medical treatment costs, per person illness in children, and lost wages for working mothers, were similar to those recommended in the literature. Lost wages in sick workers and per capita illness incidence in adults were higher than numbers reported elsewhere. Further advances in cost-benefit analysis (CBA) procedures to evaluate the economic effectiveness of NO₂ controls in Tokyo are recommended to estimate impacts and values for additional human health benefits, ecosystem health and productivity effects, and nonliving system effects, as well as benefits of ancillary reductions in other pollutants. The present study suggests that Tokyo's past NO₂ control policies in total were economically quite effective.     

Economic Benefits of Improvements in Visibility: Acid Rain Provisions of the 1990 Clean Air Act Amendments

The Acid Rain Provisions (Title IV) of the Clean Air Act Amendments of 1990 call for about a 10 million ton reduction in annual SO₂ emissions in the United States. Although the provisions apply nationwide, most of the reduction will occur in the eastern half of the country, where use of high-sulfur coal for electricity generation is most common. One potentially large benefit of Title IV is the expected improvement in visibility conditions in the eastern United States due to the reductions in secondary sul-fate aerosols. This paper combines available economic estimates of willingness to pay for improvements in visibility with current estimates of the difference between expected visibility conditions in the eastern United States with and without Title I V, to estimate the expected visibility benefits of Title IV. The results suggest an annual value of $2.3 billion (in 1994 dollars) in the year 2010, as a result of visibility improvements due to Title IV in residential areas of the eastern United States. The results also suggest a possible additional annual value for eastern U.S. residents of as much as $1-2 billion for visibility improvements at national parks in the Southeast.     

Glass Fibers and Their Use as Filter Media

Typical air quality effect levels of photochemical oxidants on specific plant substrates are illustrated. These include ambient oxidant exposure data measured as “total oxidant” as well as laboratory exposures to individual pure oxidants, ozone, or PAN compounds, since these oxidants are identified in photochemical smog. New terms, “PaNs” and “PAN-type” oxidant, have been proffered for purposes of clarification of the terminology. PAN-type oxidant more precisely defines the phytotoxicant complex causing silvering or bronzing of the lower leaf surfaces in lieu of the older term “oxidant.” Due to the recognition of several oxidizing phytotoxicants in recent years, it is recommended that the term oxidant be reserved for use as a generic term. A tabular classification of the oxidizing phytotoxicants found in community photochemical smog and the specific syndromes produced is provided.     

Economic assessment of the negative impacts of ozone on crop yields and forest production. A case study of the estate Ostads Säteri in southwestern Sweden

Ground level ozone concentrations, in combination with the prevailing climate, at the estate Ostads S?teri in southwestern Sweden were estimated to reduce the yield of wheat and potato ranging between 5% and 10%. Occasionally, in years with the highest ozone concentrations and/or climatic conditions favoring high rates of ozone uptake to the leaves, yield loss levels above 10% may occur. Based on simple extrapolation, these ozone-induced reductions of crop yields at Ostads S?teri represent a potential total annual yield loss in Sweden in the range of 24.5 million Euro for wheat and 7.3 million Euro for potato, respectively. A simulation of forest growth at Ostad S?teri predicted that prevailing mean ozone exposure during 1993-2003 had the potential to reduce forest growth by 2.2% and the economic return of forest production by 2.6%. Using this value for extrapolation to the national level, the potential annual economic loss for Sweden due to negative impacts of ozone on forest production would be in the range of 56 million Euro (2004 prices).     

Sea-Level Rise and Coastal Wetlands

This paper seeks to quantify the impact of a 1-m sea-level rise on coastal wetlands in 86 developing countries and territories. It is found that approximately 68 % of coastal wetlands in these countries are at risk. A large percentage of this estimated loss is found in Europe and Central Asia, East Asia, and the Pacific, as well as in the Middle East and North Africa. A small number of countries will be severely affected. China and Vietnam (in East Asia and the Pacific), Libya and Egypt (in the Middle East and North Africa), and Romania and Ukraine (in Europe and Central Asia) will bear most losses. In economic terms, the loss of coastal wetlands is likely to exceed $703 million per year in 2000 US dollars.     

Ozone Dosage-Crop Loss Function for Alfalfa: A Standardized Method for Assessing Crop Losses from Air Pollutants

Ozone dose-crop loss conversion functions for alfalfa (Medicago sativa, L. var. Moapa 69) yield reduction and defoliation were developed using standardized field plots within an ambient O₃ gradient in the South Coast Air Basin. Seasonal yields and defoliation values were tested with O₃ dose, average daily maximum temperature, average daily minimum temperature, and average daily relative humidity in regression analyses to determine significant functional relationships. Only the ambient O₃ dose variable was found to have a significant effect on alfalfa yield or defoliation (yield, r = –0.827, t-slope = 3.900**; defoliation, r = –0.890, t-slope = 5.190**). The ozone dose-crop loss conversion functions were calculated by converting the dose-response functions to dose-percent reduction functions.     

The effect of the increase in urban temperature on the concentration of photochemical oxidants

An atmospheric dispersion model, where the inputs of meteorological field were calculated using a meteorological model, was used to reproduce the observed air pollution conditions for the typical fine day in summer period, especially the concentration of the photochemical oxidants. As well, the effects of an increase in the urban temperature and VOC emissions on the concentration of photochemical oxidants were also considered. The following conclusions were drawn.The observed air pollution levels were well modeled by the atmospheric dispersion model using in this study, although modeled NO levels were slightly lower than the observed levels. An analysis of the temperature data showed that a 1 °C increase in temperature leads to a maximal photochemical oxidant concentration of 5.3 ppb, which is an increase of 11%. Additionally, the effect on the photochemical oxidant concentration due to an increase in the vegetation-derived VOCs was more than double the effect due to an increase in the photochemical reactions. It was found that the temperature and photochemical oxidant concentration were linearly related up to a temperature increase of 3 °C. When the temperature increases up to 3 °C, the concentration of photochemical oxidants increases by 19 ppb. An analysis of the effect of vegetation-derived VOCs on photochemical oxidant concentrations showed that, the concentration of photochemical oxidants was 30 ppb higher in the afternoon by the effect of vegetation-derived VOCs, so even in metropolitan areas with relatively little vegetation, vegetation-derived VOCs have a strong impact on photochemical oxidant concentrations.     

Contribution of Nitrate and Carbonaceous Species to PM2.5 Observed in Canadian Cities

ABSTRACT

At a variety of Canadian monitoring sites, carbonaceous compounds were estimated to account for an average of 50% of fine particle mass. These estimates were determined by subtracting the total fine particle mass associated with inorganic compounds from the total fine mass determined gravimetrically. This approach, which yields an upper limit estimate of the total amount of carbon-related mass was necessary since particulate carbon was not measured in the Canadian National Air Pollution Surveillance (NAPS) network. In this paper, total carbon estimates are evaluated against organic and elemental carbon measurements at locations in the Greater Vancouver area and Toronto. In addition, particle nitrate measurements at seven Canadian locations are used to determine the importance of nitrate relative to total mass and to examine the sampling artifacts due to the loss of particle nitrate from Teflon filters used in the NAPS di-chotomous samplers.

Measurements of organic and elemental carbon indicated that the total carbon estimation approach provides representative estimates of the average contribution by carbonaceous material to the total fine and coarse mass. The average total carbon among all Vancouver area measurements (N = 225) was 4.28 μg m^-3, while the estimated value was 4.34 μg m^-3. There was a larger discrepancy between Toronto total carbon measurements (12.1 μg m^-3) and estimates (8.8 μg m^-3), which is attributed in part to sampling of particles above 10 mm in diameter. However, the R² relating the measurements and estimates was about 0.71 for both areas. Linear regression slopes of 0.98 for Vancouver and 0.78 for Toronto (nonsignificant intercepts) indicate little bias in the Vancouver estimates, but a tendency for underestimation as the observed total carbon concentration increased in Toronto.

Annually, nitrate was responsible for 17% and 12% of the fine mass in the Vancouver area and Ontario, respectively. In contrast, at two rural locations in southern Quebec and Nova Scotia, only 6% of fine mass was associated with nitrate. Due to filter losses, nitrate concentrations determined through the NAPS dichot sampling were much lower than actual concentrations (0.44 μg m^-3 vs. 2.63 μg m^-3). As a result of these losses (attributed mostly to loss during laboratory storage), previous total carbon estimates for the Canadian NAPS sites were likely to have been overestimated on average by about 10%.