Graduate Education for Air Pollution Control Personnel

Tendergreen bean plants were grown from seeding to seed maturity under continuous exposure to HF gas at fairly uniform concentrations averaging 0.58, 2.1, 9.1, and 10.5 µg F/m³. Progeny of these plants and of comparable control plants were grown in a clean atmosphere to determine if subsequent generations were affected by HF treatment of the parents.

No effects of HF were found among the progeny of the plants grown at 0.58 µg F/m³. The F₁ generation progeny of the other HF treated plants were less vigorous than control plant progeny, as shown by later emergence, smaller primary leaves, and slower stem growth. This probably was a consequence of the lower starch content of the seed of the HF treated plants. The primary leaves of some F₁ progeny of the plants grown in the three highest HF treatments were severely stunted and distorted. This also may have been due to the low starch content of the seed, or perhaps it resulted from damage to the plumules in shriveled, distorted seed produced in these treatments.

Some of the early trifoliate leaves of many F₁ generation progeny of the plants grown at 2.1 µg F/m³ and higher were abnormal in the separation and number of their leaflets. This abnormality apparently was heritable, for in the next (F₂) generation it occurred most frequently among plants whose parents were abnormal. However, considerably fewer F₃ generation plants had abnormal trifoliate leaves, indicating rapid reversal to the normal form.     

Response of Tomato Fruiting to Hydrogen Fluoride as Influenced by Calcium Nutrition

Two varieties of tomatoes grown at 40 to 200 ppm calcium were continuously fumigated with HF throughout flowering and fruit development. Fruit size was directly related to the level of calcium nutrition, and within each calcium treatment the fruits on plants subjected to HF at about 6 μg F/m³ were smaller than those on unfumigated plants. The smaller fruit size was associated with partial or complete seedlessness, suggesting that calcium plays an essential role in fertilization with which fluoride may interfere. Fluoride injury to the tomato foliage was most severe at the lowest calcium level. Treatment with HF at about 8 μg F/m³ produced some injury to tomato foliage but had no apparent effect on fruiting. Evidently fluoride can affect plant fruiting, but considering the severity of the HF treatments required, effects on tomato fruiting probably are of little practical significance. The relationship between fluoride injury and calcium nutrition suggests interference with calcium metabolism as a mechanism of fluoride injury to plants.     

Physiological characteristics of <Emphasis Type="Italic">Plantago major</Emphasis> under SO<Subscript>2</Subscript> exposure as affected by foliar iron spray

Sulfur dioxide (SO₂) is considered as a main air pollutant in industrialized areas that can damage vegetation. In the present study, we investigated how exposure to SO₂ and foliar application of iron (Fe) would affect certain physiological characteristics of Plantago major. The plant seedlings exposed or unexposed to SO₂ (3900 μg m^?3) were non-supplemented or supplemented with Fe (3 g L^?1) as foliar spray. Plants were exposed to SO₂ for 6 weeks in 100 × 70 × 70 cm chambers. Fumigation of plants with SO₂ was performed for 3 h daily for 3 days per week (alternate day). Lower leaf Fe concentration in the plants exposed to SO₂ at no added Fe treatment was accompanied with incidence of chlorosis symptoms and reduced chlorophyll concentration. No visible chlorotic symptoms were observed on the SO₂-exposed plants supplied with Fe that accumulated higher Fe in their leaves. Both at with and without added Fe treatments, catalase (CAT) and peroxidase (POD) activity was higher in the plants fumigated with SO₂ in comparison with those non-fumigated with SO₂. Foliar application of Fe was also effective in increasing activity of antioxidant enzymes CAT and POD. Exposure to SO₂ led to reduced cellulose but enhanced lignin content of plant leaf cell wall. The results obtained showed that foliar application of Fe was effective in reducing the effects of exposure to SO₂ on cell wall composition. In contrast to SO₂, application of Fe increased cellulose while decreased lignin content of the leaf cell wall. This might be due to reduced oxidative stress induced by SO₂ in plants supplied with Fe compared with those unsupplied with Fe.     

Atmospheric deposition of fluoride in the lower Tamar Valley,Tasmania

Soluble fluoride (F⁻), measured using an ion-selective electrode, was monitored during 1982–1983 in monthly bulk (wet and dry) atmospheric deposition samples collected at 17 locations in the lower Tamar Valley, Tasmania, where an aluminium (Al) smelter is located. Glass samplers (funnel-bottle type) were used, with duplications by plastic samplers at five locations later. The spatial and temporal variations in F⁻ deposition in relation to wind flow and rainfall are discussed, and its impact on the environment is highlighted. The mean deposition rates of F⁻, as measured from September 1982 to August 1983, ranged from about 90 μg m⁻² day⁻¹ at the intended ‘background’ location to 12,568 μg m⁻²day⁻¹ at a location about 1 km east-southeast from the smelter. The depositional fluxes of F⁻ and insoluble Al (another elemental tracer of the smelter) are significantly correlated (P < 0.001). They were much higher within 3 km of the smelter, where vegetation damage by fluoride contamination was most evident. However, air emissions from the smelter could travel at least 10 km up the valley. Wet deposition was the predominant removal process for F⁻ during autumn and winter, while dry deposition appeared to be more significant in summer. The plastic samplers collected about 8 and 17% more F⁻ and Al, respectively, but with higher standard deviations. Thus the variations observed could be largely due to sampling fluctuations.     

Severity of SO2-lnduced Leaf Necrosis on Caribbean,Scots, and Virginia Pine Seedlings

Caribbean pine, an economically important tree of tropical lowlands, is at risk of SO₂ exposure in certain locales. Twenty-week old seedlings of Caribbean, Scots, and Virginia pine were exposed to 0.5, 1.0, and 2.0 ppm SO₂ (1300, 2600, and 5200 μm^?3, respectively) for 1, 2, 4, and 8 h in modified controlled-environment chambers. Severity of SO₂-induced leaf necrosis for each species was related to SO₂ concentration and exposure duration using a regression model. The three dose-response relationships differed in detail, but Caribbean pine seedlings were generally as sensitive to SO₂ as seedlings of the two highly sensitive temperate species. In addition, 173 4-wk-old Caribbean pine seedlings were exposed to 0.5 ppm SO₂ for 4 h. Over one-half of these seedlings exhibited some necrosis and over one-sixth had more than 5 percent of leaf surface necrotic. It is concluded that Caribbean pine seedlings are highly sensitive to acute doses of SO₂.     

An Air Quality Data Analysis System for Interrelating Effects,Standards, and Needed Source Reductions: Part 3. Vegetation Injury

Acute leaf injury data are analyzed for 19 plant species exposed to ozone or sulfur dioxide. The data can be depicted by a new leaf injury mathematical model with two characteristics: (1) a constant percentage of leaf surface is injured by an air pollutant concentration that is inversely proportional to exposure duration raised to an exponent; (2) for a given exposure duration, the percent leaf injury as a function of pollutant concentration tends to fit a lognormal frequency distribution. Leaf injury as a function of laboratory exposure duration is modeled and compared with ambient air pollutant concentration measurements for various averaging times to determine which exposure durations are probably most important for setting ambient air quality standards to prevent or reduce visible leaf injury. The 8 hour average appears to be most important for most of the plants investigated for most sites, 1 hr concentrations are important for most plants at a few sites, and 3 hr S0₂ concentrations are important for some plants, especially those exposed to isolated point sources of the pollutant. The 1, 3, and 8 hr threshold injury concentrations are listed for each of the 19 plant species studied. To prevent or reduce acute leaf injury, fixed, nonoverlapping ambient air quality measurements and standards are recommended for averaging times of 1, 3, and 8hr.     

Leaf conductance response of phaseolus vulgaris to ozone flux density

The effect of ozone flux density on leaf conductance to ozone in Phaseolus vulgaris was examined. The change in conductance was measured within the first two hours of fumigation for mature, fruiting 6-week-old plants of an ozone sensitive cultivar (Seafarer); for young, 14-day-old plants of the same cultivar; and for an ozone resistant cultivar (Gold Crop). Young Seafarer plants showed no change in conductance to ozone over a wide range of ozone flux densities. Gold Crop showed a decrease in conductance of −3.1 % /(mgO₃ m⁻² h⁻¹) whereas mature Seafarer plants exhibited a stronger decrease of −7.7% /(mgO₃ m⁻² h⁻¹). Diffusion porometer measurements taken on fruiting Seafarer plants in the field illustrated that a decrease in leaf diffusive conductance to water is related to visual ozone injury.     

Some Effects of Atmospheric Fluoride on Plant Metabolism

Leaves of Tendergreen bean plants exposed to atmospheric fluoride concentrations in the range 1.7 to 7.6 μg/m³ showed increased levels of enolase and catalase activity and decreased levels of pyruvate and α-ketoglutarate. Phosphoenolpyruvate carboxylase activity and oxalacetate were not affected. The leaves of Milo maize plants exposed to 5.0 μg F/m³ showed increased levels of enolase and pyruvate kinase activity and a decreased level of pyruvate. Oxalacetate and α-ketoglutarate levels were not affected. Catalase activity was increased, then decreased by IIF fumigation. The changes induced by HF were greatest six to 10 days after the start of fumigation and disappeared or decreased in magnitude during the post-fumigation period.     

Development of a modified factor analysis/multiple regression model to apportion suspended particulate matter in a complex urban airshed

A modified factor analysis/multiple regression (FA/MR) receptor-oriented source apportionment model has been developed which permits application of FA/MR statistical methods when some of the tracers are not unique to an individual source type. The new method uses factor and regression analyses to apportion non-unique tracer ambient concentrations in situations where there are unique tracers for all sources contributing to the non-unique tracer except one, and ascribes the residual concentration to that source. This value is then used as the source tracer in the final FA/MR apportionment model for ambient paniculate matter. In addition, factor analyses results are complemented with examination of regression residuals in order to optimize the number of identifiable sources.The new method has been applied to identify and apportion the sources of inhalable particulate matter (IPM; D₅₀15 μm), Pb and Fe at a site in Newark, NJ. The model indicated that sulfate/secondary aerosol contributed an average of 25.8 μ⁻³ (48%) to IPM concentrations, followed by soil resuspension (8.2 μ⁻³ or 15%), paint spraying/paint pigment (6.7/gmm⁻³or 13%), fuel oil burning/space heating (4.3 μ⁻³ or 8 %), industrial emissions (3.6 μm⁻³ or 7 %) and motor vehicle exhaust (2.7 μ⁻³ or 15 %). Contributions to ambient Pb concentrations were: motor vehicle exhaust (0.16μm⁻³or 36%), soil resuspension (0.10μm⁻³ or 24%), fuel oil burning/space heating (0.08μm⁻³or 18%), industrial emissions (0.07 μ⁻³ or 17 %), paint spraying/paint pigment (0.036 μm⁻³or 9 %) and zinc related sources (0.022 μ⁻³ or 5 %). Contributions to ambient Fe concentrations were: soil resuspension (0.43μ⁻³or 51%), paint spraying/paint pigment (0.28 μm⁻³or 33 %) and industrial emissions (0.15 μ⁻³or 18 %). The models were validated by comparing partial source profiles calculated from modeling results with the corresponding published source emissions composition.     

Presence of alkyllead in rural and urban air: Evaluation of some sources of alkyllead pollution of the atmosphere in Norway

Concentrations of alkyllead in ambient air were measured, as well as in car exhaust and in gasoline vapours. In Oslo the concentration in air ranged from 0.010 to 0.100 μg Pb m⁻³, and these values were compared to the concentrations (< 0.001 μg Pb m⁻³) measured in a low traffic rural area of Norway. The amount of alkyllead in car exhaust varied between 0.1 and 15 μg Pb m⁻³, which was between 0.01 and 0.5% of the amount of inorganic lead in exhaust. Evaporation of alkyllead from parked cars was estimated at 0.5 mg Pb per day per car. The concentrations of alkyllead in saturated gasoline vapour were found to be 10–20 mg Pb m⁻³ at ambient air temperatures.     

Benzene exposure in Helsinki,Finland

Personal exposures and microenvironmental concentrations of benzene were measured in the residential indoor, residential outdoor and workplace environments for 201 participants in Helsinki, Finland, as a component of the EXPOLIS-Helsinki study. Median benzene personal exposures were 2.47 (arithmetic standard deviation (ASD)=1.62) μg m⁻³ for non-smokers, 2.89 (ASD=3.26) μg m⁻³ for those exposed to environmental tobacco smoke in any microenvironment and 3.08 (ASD=10.04) μg m⁻³ for active smokers. Median residential indoor benzene concentrations were 3.14 (ASD=1.51) μg m⁻³ and 1.87 (ASD=1.93) μg m⁻³ for environments with and without tobacco smoke, respectively. Median residential outdoor benzene concentrations were 1.51 (ASD=1.11) μg m⁻³ and median workplace benzene concentrations were 3.58 (ASD=1.96) μg m⁻³ and 2.13 (ASD=1.49) μg m⁻³ for environments with and without tobacco smoke, respectively. Multiple step-wise regression identified indoor benzene concentrations as the strongest predictor for personal benzene exposures of those not exposed to tobacco smoke, followed sequentially by time spent in a car, time in the indoor environment, indoor workplace concentrations and time in the home workshop. Relationships between indoor and outdoor microenvironment concentrations and personal exposures showed considerable variation between seasons, due to differences in ventilation patterns of homes in these northern latitudes. Automobile use-related activities were significantly associated with elevated benzene levels in personal and indoor measurements when tobacco smoke was not present, which demonstrates the importance of personal measurements in the assessment of exposure to benzene.     

Influence of Sulfur Dioxide and Hydrogen Fluoride as a Mix or Reciprocal Exposure on Citrus Growth and Development

The influence of exposure to mixtures of SO₂ and HF on Koethen sweet orange and mixtures and alternate exposure to these gases on Satsuma mandarin were tested using a rotating fumigation greenhouse. Effects of HF-SO₂ mixtures on linear growth and leaf area of Koethen orange were additive, not synergistic. No necrosis was observed on Koethen oranges exposed to HF, SO₂, or a mixture of HF and SO₂. Effects of the mixture on chlorosis of Satsuma mandarin foliage was also not synergistic. No significant difference in linear growth of Satsuma mandarin was found among all treatments. Alternate exposure to SO₂ followed by HF produced no synergistic injury to Satsuma mandarin. Satsuma mandarin appeared more sensitive than Koethen orange to HF, SO₂, and mixtures of these two gases using degree of chlorosis and leaf abscission as the criteria of sensitivity. If iinear growth and leaf area were the principal criteria considered, Koethen orange would appear more sensitive.     

Variation in the relationship between blood lead and air lead

Estimates of the slope of the relationship between blood lead (μg dl⁻¹) and air lead (μg m⁻³) obtained in ten independent studies are compared. No significant differences were detected among the estimates which ranged from 0.6 to 3.1 μg dl⁻¹ per μg m⁻³ and represented male adult, female adult and child populations. A single best estimate of 1.2 μg dl⁻¹ per μg m⁻³ ( ± 0.2,95 per cent confidence limits) was obtained. It is concluded that, if the blood lead-air lead slope depends on various physical and biological factors, then studies providing more precise estimates are required to detect these differences.     

Effects of vapours of chlorpropham and ethofumesate on wild plant species.

Effects of vapours of two herbicides on plantlets of fourteen wild higher plant species and two bryophytes were screened in fumigation experiments using foliar injury, chlorophyll fluorescence and growth as response parameters. After vaporisation of the herbicides for 48 h, concentrations in the chambers reached 77 micrograms m-3 in the chlorpropham treatments and 184 ng m-3 in the ethofumesate treatments. Despite the higher concentrations of the volatile chlorpropham (vapour pressure, VP: 1.3 mP), plants showed no foliar injury, but vapours of this herbicide caused leaf crinkling in the agriophyte Agrostemma githago. The less volatile ethofumesate (VP: 0.56 mP) caused foliar injury in all higher species, with lowest no observed effect concentrations (NOECs) of 75 ng m-3. Chlorpropham affected growth only in Agrostemma, while ethofumesate reduced growth in one third of the higher plant species. Chlorophyll fluorescence proved to be a less suitable response parameter compared to foliar injury and growth. No adverse effects were observed in mosses, probably due to the slow growth and hence small doses of herbicides taken up. The extent of foliar injury due to ethofumesate showed a weak positive relationship to relative growth rates and specific leaf area in the tested higher plant species.     

Speciation and pulmonary effects of acidic SOx formed on the surface of ultrafine zinc oxide aerosols

Ultrafine metal oxides and SO₂ react during coal combustion or smelting operations to form primary emissions coated with an acidic SO_x layer. A ZnO-SO₂-H₂O (mixed 500°C) system generates such particles to provide greatly needed information on both quantitative composition of the surface layer and its effects on the lung. Total S on the particles is related to ZnO concentration and is predominantly S^VI. As a surface layer, 20 μg m⁻³ H₂SO₄ decreases pulmonary diffusing capacity in guinea pigs after four daily 3-h exposures and produces bronchial hypersensitivity following a single 1-h exposure. That 200 μg m⁻³ H₂SO₄ aerosols of equivalent particle size are needed to produce the same degree of bronchial hypersensitivity emphasizes the importance of the surface layer.     

An experimental study of the dry deposition of gaseous nitric acid to snow

A chamber placed in a constant temperature freezing room was used to study the surface resistance during deposition of HNO₃ to a snow surface. The resistance decreased with increasing temperature from larger than 5 s mm⁻¹ at − 18°C to about l s mm⁻¹ at −3°C. Measurements of gaseous and particulate nitrate concentrations during winter at a rural site in south central Sweden gave concentrations in the range of 0.4–5 μg HNO₃ m⁻¹ and 0.3–3 μg NO⁻₃ m⁻³ with a mean value of 1.3 μg HNO₃ m⁻³ and 0.7 μg NO⁻₃ m⁻³, respectively. The results indicate that for periods with temperatures below − 2°C estimated dry deposition of HNO₃ to snow is at most 4 % of measured wet deposition of nitrate in the area.     

FTIR transmission spectrometry for the nondestructive determination of ammonium and sulfate in ambient aerosols collected on teflon filters

Fourier transform infrared (FTIR) transmission spectrometry has been used to determine ammonium and sulfate in ambient aerosol particles collected on Teflon filters. Integrated absorbance as well as maximum absorbance values for ammonium and sulfate are linearly related to X-ray fluorescence measurements of total sulfur. Apparent detection limits of 1.4 μg m⁻³ for sulfate and 0.5 μg m⁻³ for ammonium (for sample volumes of 21.6 m³) were estimated for samples from Topeka, Kansas; Portage, Wisconsin; Steubenville, Ohio; and Charlottesville, Virginia. The apparent detection limits were essentially independent of sample loading over the range of 0–20 μg m⁻³ of total sulfur. The FTIR transmission measurements of these samples are very precise e.g. repetitive measurements vary ± 0.2% and blank variability is 0.13 μg m⁻³ and 0.20 μg m⁻³ in terms of sulfate and ammonium, respectively. Contributions to analytical uncertainty include 5–8% uncertainties in X-ray fluorescence measurements for total sulfur and the influence of unspecified site-dependent sample characteristics. The method offers the significant advantages of nondestructive analysis, no sample preparation, molecular speciation and rapid analysis.     

The contribution of elemental carbon to the optical properties of rural atmospheric aerosols

Measurements of carbonaceous aerosol, aerosol light absorption and aerosol light scattering were made at two rural sites in southwestern Pennsylvania during August 1983. Aerosol light absorption ranged from 5.2 × 10⁻⁶ m⁻¹ to 6.4 × 10⁻⁵ m⁻¹ (average: 1.9 × 10⁻⁵ m⁻¹) and accounted for about 13% of the aerosol total light extinction. Elemental carbon, averaging 1.3 μg m⁻³ at the two sites (and comprising some 36 % of the aerosol carbon), accounted for effectively all (> 95 %) of the aerosol light absorption.     

A flux-based assessment of the effects of ozone on foliar injury, photosynthesis, and yield of bean (Phaseolus vulgaris L. cv. Borlotto Nano Lingua di Fuoco) in open-top chambers

Stomatal ozone uptake, determined with the Jarvis' approach, was related to photosynthetic efficiency assessed by chlorophyll fluorescence and reflectance measurements in open-top chamber experiments on Phaseolus vulgaris. The effects of O₃ exposure were also evaluated in terms of visible and microscopical leaf injury and plant productivity. Results showed that microscopical leaf symptoms, assessed as cell death and H₂O₂ accumulation, preceded by 3-4 days the appearance of visible symptoms. An effective dose of ozone stomatal flux for visible leaf damages was found around 1.33 mmol O₃ m⁻². Significant linear dose-response relationships were obtained between accumulated fluxes and optical indices (PRI, NDI, ΔF/F_m^′). The negative effects on photosynthesis reduced plant productivity, affecting the number of pods and seeds, but not seed weight. These results, besides contributing to the development of a flux-based ozone risk assessment for crops in Europe, highlight the potentiality of reflectance measurements for the early detection of ozone stress.     

Direct Effects of Atmospheric Sulfate Deposition on Vegetation

Acid sulfate aerosol (500 μg/m³) had no effect on soybean or pinto bean after a single 4-h exposure. However, visible Injury and chlorophyll loss occurred when plants were sequentially exposed to acid aerosol and ozone (380 μg/m³) for 4 h. In yellow poplar seedlings exposed to ozone (200 μg/m³), sulfur dioxide (210 μg/m³) and simulated rain solutions (pH 5.6, 4.3 and 3.0) for 6 weeks, root dry weight, leaf area increase, mean relative growth rate and unit leaf rate decreased linearly with pH in ozone-treated plants. However, unit leaf rate and mean relative growth rate increased linearly in response to sulfur dioxide as solution acidity increased. Ambient wet and dry sulfate concentrations appear insufficient to directly impact vegetation.