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Combustion emissions and strong Santa Ana winds had pronounced effects on patterns and levels of ambient ozone (O3) in southern California during the extensive wildland fires of October 2007. These changes are described in detail for a rural receptor site, the Santa Margarita Ecological Reserve, located among large fires in San Diego and Orange counties. In addition, O3 changes are also described for several other air quality monitoring sites in the general area of the fires. During the first phase of the fires, strong, dry and hot northeasterly Santa Ana winds brought into the area clean continental air masses, which resulted in minimal diurnal O3 fluctuations and a 72-h average concentration of 36.8 ppb. During thesecond phase of the fires, without Santa Ana winds present and air filled with smoke, daytime O3 concentrations steadily increased and reached 95.2 ppb while the lowest nighttime levels returned to w0 ppb. During that period the 8-h daytime average O3 concentration reached 78.3 ppb, which exceeded the federal standard of 75 ppb. After six days of fires, O3 diurnal concentrations returned to pre-fire patterns and levels.

Since the mid-1950s, native pines in the San Bernardino Mountains (SBM) in southern California have shown symptoms of decline. Initial studies in 1963 showed that ozone (O3) generated in the upwind Los Angeles Basin was responsible for the injury and decline of sensitive trees. Ambient O3decreased significantly by the mid-1990s, resulting in decreased O3injury and improved tree growth. Increased growth of trees may also be attributed to elevated atmospheric nitrogen (N) deposition. Since most of the N deposition to mixed conifer forest stands in the SBM results from dry deposition of nitric acid vapor (HNO3) and ammonia (NH3), characterization of spatial and temporal distribution of these two pollutants has become essential. Although maximum daytime O3concentrations over last 40 years have significantly decreased (~3-fold), seasonal means have been reduced much less (~1.5-fold), with 2-week long means occasionally exceeding 100 ppb in the western part of the range. In the same area, significantly elevated concentrations of HNO3and NH3, up to 17.5 and 18.5 μg/m3as 2-week averages, respectively, have been determined. Elevated levels of O3and increased N deposition together with long-term drought predispose the SBM forests to massive bark beetle attacks making them susceptible to catastrophic fires.

Nitric acid (HNO3) vapor is a significant component of air pollution. Dry deposition of HNO3 is thought to be a major contributor to terrestrial loading of anthropogenically-derived nitrogen (N), but many questions remain regarding the physico-chemical process of deposition and the biological responses to accumulation of dry-deposited HNO3 on surfaces. To examine these processes experimentally, a continuously stirred tank reactor (CSTR) fumigation system has been constructed. This system enables simultaneous fumigation at several concentrations in working volumes 1.3 m dia by 1.3 m ht, allowing for simultaneous fumigation of many experimental units. Evaluation of the system indicates that it is appropriate for long-term exposures of several months duration and capable of mimicking patterns of diurnal atmospheric HNO3 concentrations representative of areas with different levels of pollution.

L-arginine cardioplegia decreases biochemical markers of myocardial damage and oxidative stress in patients with normal left ventricular function. We investigated the effects of L-arginine supplemented cardioplegic arrest in patients with reduced ejection fraction. Fifty-three adult patients with left ventricular ejection fraction −1 (15 minutes) (P=0.0004). Superoxide dismutase activity was higher in L-arginine group, 229±87 vs 191.3±68 (5 minutes), 229±54 vs 198±15 nmol.minute−1.ml (15 minutes) (P=0.005). Lactic acid flux was lower in the L-arginine group, 0.15±0.23 vs 0.48±0.32 (1 minute), 0.08±0.19 vs 0.38±0.31 (5 minutes) and −0.15±0.13 vs 0.26±0.30 mmol.l−1 (15 minutes), (P=0.0003). There was no difference in left ventricular systolic function. The mitral annular tissue Doppler inflow (eʹ) velocity during early diastole improved in the L-arginine group following cardiopulmonary bypass (control 4.2±1.9 cm.s−1 to 3.6±1.2 cm.s−1 vs L-arginine 3.8±1.2 cm.s−1 to 4.6±1.4 cm.s−1) (P=0.018). In patients with reduced ejection fraction, L-arginine supplemented cardioplegic arrest did not affect postoperative cardiac troponin-I levels, but attenuated cardiac cellular peroxidation and improved early left ventricular diastolic function.

Young 'Valencia' orange trees (Citrus sinensis(L) Osbeck) were grown for four years in large open-top chambers with ambient (nonfiltered) air or in outside air to determine any effects of the chambers on the air pollutant susceptibility of the trees. Long-term ozone average concentrations (12 hours, growing season) were 8% lower, and cumulative ozone dose (hourly values >0.1 microL/L) was 29% lower in ambient chambers compared to outside air. Fruit yields were much higher (>39%) for ambient chamber trees than for outside trees over three harvests, due at least partly to less fruit drop during the growing season for ambient chamber trees. Ambient chamber trees were much larger than outside trees and produced over twice as much leaf material over four years of study. Leaves on ambient chamber trees were larger and less dense than on outside trees. Leaves on ambient chamber trees were under more stress than leaves on outside trees during summer months; with lower stomatal conductances (14% average) and transpiration rates (12%), and more negative leaf water pressure potentials (28%). In contrast, leaves on ambient chamber trees had higher net photosynthetic rates (13%) and higher leaf starch concentrations prior to tree flowering (31%), than leaves on outside trees. more » While these results indicated large long-term impacts on tree growth which must be considered when using open-top chambers, they did not indicate any net effect of chambers on the air pollutant susceptibility of trees which would limit the usefulness of chamber tree data for air quality impact assessment purposes. « less

Atmospheric dry deposition of ions to branches of native Pinus contorta and Pinus monticola (natural surfaces), and nylon filters and Whatman paper filters (surrogate surfaces) were measured in the summer of 1987 in the vicinity of Emerald Lake Watershed (ELW) of the Sequoia National Park located on the western slope of the Sierra Nevada in California. Deposition fluxes of airborne NO−3, NH+4 and SO2−4 to native pines at the ELW were much higher than in the eastern Sierra Nevada, but several times lower than deposition fluxes to natural and surrogate surfaces at the highly polluted site in the San Gabriel Mountains of southern California. Deposition fluxes of NO3− and NH4+ to the natural and surrogate surfaces at the ELW were much higher than deposition of SO42−, providing the importance of N compounds in atmospheric dry deposition in this part of the western U.S. A deficit of inorganic anions in materials deposited to various surfaces indicated a possibility of substantial participation of organic acids in atmospheric dry deposition processes. Nylon and paper filters proved to be poor surrogate surfaces for the estimation of ionic dry deposition to conifer branches.

Three-year-old ‘Valencia’ orange [Citrus sinensis (L.) Osbeck] trees were exposed to air pollutants for 4 . years in open-top field chambers to determine the chronic effects of ambient oxidants (primarily ozone) or sulfur dioxide (SO2) on fruit yield and quality and tree growth. Ozone concentrations averaged 0.012,0.040, and 0.075 ppm for 0800 to 2000 HR during April to October for filtered, half-ambient, and full ambient oxidant chambers. Sulfur dioxide was applied continuously at 0.09 ppm. Oxidant and SO2 effects were only marginally significant, as there was considerable variability in response among individual trees and between years. Across two “on” production years, yields were 31% lower with ambient oxidants, 11% lower with half-ambient oxidants, and 29% lower with sulfur dioxide compared to filtered air. Number of fruit per tree was reduced by ambient oxidants and SO2. Individual fruit weights were reduced by ambient oxidants, but no other fruit quality characteristics showed definite responses to ambient oxidants or SO2. Ambient oxidants had no effect on yield or quality of fruit during one “off’ production year. Neither ambient oxidants nor SO, affected tree growth. During the late 1950s and early 1960s, researchers conducted pioneer studies on the chronic (low-level, long-term) effects of photochemical oxidants on navel oranges and lemons near Los Angeles (Thompson et al., 1967; Thompson and Taylor, 1969). These studies showed reduced water use, increased leaf drop, and very substantial reductions in yields of both species due to photochemical oxidants. Losses in production occurred even though there were few easily observed leaf injury symptoms on the trees. The sensitivity of orange trees to ambient pollutants in the previous studies, however, may have been different from that of outside trees since the experiments were conducted in closed, plastic-covered greenhouses. The trees were exposed only to filtered or ambient air, with little accurate air monitoring data for the different treatments. Thus, it was not possible to produce accurate dose-response models to describe the relationship between oxidant dose (measured as ozone, O3) and yield. Such models have become necessary for interpreting current oxidant and orange yield data for loss assessments (Olszyk et al., 1988). The susceptibility of oranges to long-term, low-level chronic exposure to sulfur dioxide (SO2), as could occur near oil refineries and other point sources, has not been well-documented. Thomas (1961) cited results of O’Gara who reported citrus to be very resistant to acute foliar injury by SO2 compared to 100 other crop, ornamental, or forest species tested. Matsushita and Harada (1964, 1966) found that exposures of three species of l-year-old citrus to 1 and 5 ppm SO2 for 2 hr·day -1 for 40 days caused no foliar injury. However, we found no reports detailing chronic long-term exposures with low concentrations

(1990). Plant Response to Nonfiltered Air vs. Added Ozone Generated from Dry Air or Oxygen. Journal of the Air & Waste Management Association: Vol. 40, No. 1, pp. 77-81.

Ozone was applied to sealed red cell ghost membranes at the rate of 95 nmol/min for periods up to 20 min. Acetylcholine esterase, on the outer face of the membrane, was inhibited up to 20%. Glyceraldehyde-3-phosphate dehydrogenase, on the inner surface of the membrane, was inhibited up to 87%. These differences reflected the inherent susceptibilities of the two enzymes and the presence or absence of the membrane barrier. Analysis of the total lipids of the ozone-treated ghosts showed no significant change in the distribution of lipid classes and no significant change in the fatty acid composition. There was no significant change in the fatty acid composition of the phosphatidylcholine fraction. There was a slight increase in 18:0 and 20:2 + 20:3 in the phosphatidylethanolamine fraction. There was no change in the molecular species distribution of the phosphatidylcholine or the phosphatidylethanolamine fraction. There was no evidence for the formation of the phospholipid ozonolysis product, 1-acyl-2-(9-oxo-nonanyl) derivatives of glyceryl-phosphoryl choline. There was no decline in the amount of cholesterol in the lipids derived from ozone-treated red cell membranes. Treatment of red cell ghost membranes and, by implication, the plasma membrane of cells by ozone therefore oxidizes peripheral proteins before it oxidizes lipids.

Ozone is a widespread component of polluted air. It is the cause of many adverse effects on the lung such as decreased athletic performance and exacerbation of asthma. Ozone inactivated acetylcholine esterase (AChE) both in intact washed human erythrocytes and in ghosts prepared from the erythrocytes. This is consistent (a) with the location of AChE on the outer face of the membrane and (b) with the change in structure of AChE when amino acids were oxidized. The glyceraldehyde-3-phosphate dehydrogenase (G3PDH) of intact washed erythrocytes was unaffected by ozone. However, ozone severely inactivated G3PDH of ghosts, much more severely than AChE in ghosts. This result raised questions about the relative permeability of intact erythrocytes and ghosts and also about the inherent susceptibility of the two enzymes. Inhibition of the ozone-treated erythrocyte AChE with the competitive inhibitor trimethyl-(p-aminophenyl) ammonium chloride was measured. The inhibited enzyme had a higher K(M) and slightly lower Vmax than the control. Ozone did not affect the K(M) of the uninhibited enzyme but decreased the K(M) of the inhibited enzyme. Ozone decreased the Vmax of both the inhibited and the uninhibited enzyme. The K(I) was unchanged by the treatment with ozone. This suggested that the active site of the enzyme was not affected by ozone, but other features of the protein were changed by ozone. The effects of products of lipid ozonolysis [hydrogen peroxide, nonanal, and 1-palmitoyl-2-(9-oxononanyl)-sn-3-glycerophosphorylcholine (PN1PC)] were tested on the ghost preparations. The ozonolysis products were tested at concentrations equivalent to calculated amounts that could have been produced by ozone. Hydrogen peroxide had no effect on the G3PDH and AChE. Nonanal slightly increased the permeability of the ghost membrane, as judged by the increase in rate of G3PDH in the absence of Triton X-100, but did not inhibit enzyme activity. PN1PC increased the permeability of the ghosts, as judged by the increase in rate of G3PDH in the absence of Triton X-100. There was also an increase in the activity of G3PDH in the presence of Triton X-100. AChE was not inhibited by ozone in the presence or absence of Triton X-100.

Fentanyl and bupivacaine were tested for their stability when diluted with 0.9% sodium chloride to 4 micrograms ml-1 and 0.1% respectively, in 100-ml polyvinyl chloride (PVC) bags, alone and in combination, with and without adrenaline 1:200,000. Changes in drug concentration and pH were investigated for 56 days. The combination of fentanyl, bupivacaine and adrenaline was tested under varying environmental conditions of 35 degrees C, 4 degrees C, -18 degrees C, room temperature, darkness and after autoclaving. Fentanyl and bupivacaine were adsorbed onto PVC, resulting in reductions of 12.6% and 9.6% drug mass, respectively, at day 3, but remained stable thereafter. Adrenaline was progressively degraded to a maximum reduction of 37.3% at 35 degrees C by day 56. Solutions containing adrenaline became more acidic over 56 days. Fentanyl and bupivacaine were stable.

Twenty patients were given maximal doses of atracurium or vecuronium by infusion during surgery. Anaesthesia was maintained with an infusion of thiopentone, nitrous oxide and fentanyl. In patients administered atracurium, the plasma laudanosine concentration at cessation of surgery was 0.34 (SD 0.22) micrograms ml-1; there was little tendency to cumulate during operation. A 20% higher arterial concentration of thiopentone was found at awakening in patients given atracurium, suggesting CNS stimulation by laudanosine, although the effect is too modest to be of clinical significance.

An air exclusion system was designed, constructed, and tested to determine its effectiveness in studies of air pollutant effects on vegetation. The air exclusion system was shown to be an effective alternative to open-top field chambers for controlled exposures of air pollutants to low growing plants. The system design included particulate and activated charcoal filters, pressure-type blowers, a mixing manifold, and perforated inflatable ducts that were positioned between rows of plants. Tests with CO as a tracer gas indicated optimal system parameters for air exclusion including: air flow of at least 0.944 m³ s⁻¹ within the ducts, three or four rows of holes on the side of each duct pointing 45° upward, 90° to the side, and 45° downward from the center of the duct, four ducts per system, and a hole size that provided an air velocity of 0.5 to 1.8 m s₋₁ over the plant canopy. Reductions of > 70% in ambient O³ concentrations could be achieved over the plant canopy at 0.25 m above the ground with the air exclusion system under optimum conditions (low ambient wind speed and high ambient ozone concentrations). This was comparable to the reductions achieved with either open-top or closed-top chambers. A gradient in ozone concentrations was obtained within a single system by delineating the ducts into three sections with different sized holes. Sulfur dioxide was added to a modified system to provide a gradient of 0, 0.03, 0.07, and 0.15 µL SO₂ L⁻¹ over a winter growing season. No large environmental differences were found between air exclusion systems and open-top chambers vs. outside plots in the summer. In the fall and winter, open-top chambers had higher air, leaf, and soil temperatures than air exclusion sytems or outside plots. Air speed over the plant canopy was higher with the air exclusion system than in open-top chambers or outside plots.

In order to assess concentrations and daily patterns of air pollutants at a mountainous site in the South Coast Air Basin, a study was undertaken in the San Dimas Experimental Forest of the San Gabriel Mountains between April 1985 and October 1985. Continuous monitoring of O3, NO, NO2, SO2, total S compounds and light scattering coefficient was conducted. Particulate aerosols were collected twice a week and concentrations of nitrate, ammonium and sulfate in fine ( 2.5 μm diameter) modes were determined. For the June–August period, when the levels of photochemical smog were the highest, monthly 24-h average concentrations of the pollutants were: O3, about 200 μg m−3; NO2, 40–75 μg m−3; NO, 1–5 μg m −3; and SO2, 0.5–5 μgm−3. The concentrations of O3 were about two times higher than in the neighboring stations of the South Coast Air Basin. O3, SO2 and total S concentrations peaked in the early afternoon, generally between 1500 and 1600 PST. Peak concentrations of NO occurred in the morning, generally between 1000 and 1100 PST. NO2 concentrations typically peaked in the late afternoon between 1500 and 1800 PST, but occasionally (in 9 % of days) maximum NO2 occurred in the morning, concurrently with the NO peaks. Daytime concentrations of the nitrate in fine aerosol fraction were generally between 100 and 600 nEq m −3, those of ammonium between 50 and 300 nEq m −3, and concentrations of sulfate between 60 and 250 nEq m−3. A 3-day denuder study showed that HNO3can make up to 73 % of the total amount of total nitrate in the air. NO2 was the most abundant N compound at Tan bark Flat (69–86% of the total amount of the monitored N compounds). Nitrate amounted to 9–15 %, HNO3 to 4–11 %, ammonium to 3–9%, and NO to 1–2% of the total amount of the measured nitrogen compounds.

Three cultivars of rice, Oryza sativa, M7, M9 and S201 were exposed in open-top field chambers to ozone and sulfur dioxide to determine the effects of these important air pollutants on field-grown plants. Exposures were for 15 weeks with ozone at 0, 98, 196, 294 or 392 μg m−3 for 5 h day−1, 5 days week−1, and sulfur dioxide at 131, 262, 393 or 524 μg m−3 for 24 h day−1, 5 days week−1. Three harvests of rice were made after 27 and 68 days and at the end of the exposures. At the first harvest following early plant growth, ozone at the highest concentrations resulted in reductions in growth whereas sulfur dioxide resulted in increased growth. At the second harvest, ozone-exposed plants continued to show reduced growth, whereas sulfur dioxide resulted only in reduced plant height. At the final and major harvest, ozone at 392 μg m−3 reduced total seed weight 12, 29 and 21% in cultivars M7, M9 and S201, respectively. Weight of 100 seeds and straw weight were reduced in M9 and S201 and percent seed sterility in panicles was increased. Ozone reduced height of all cultivars and increased the number of panicles. Sulfur dioxide at 524 μg m−3 reduced total seed weight of M9 and S201 by 22 and 14%, respectively, and weight per hundred seed by 11 and 10%, respectively. The results showed that ozone is much more injurious to rice per unit of pollutant than sulfur dioxide and that reduced yield due to both pollutants was caused mostly by reduced seed size. Increased seed sterility was partially offset by ozone exposure of the plants which produced more panicles. Cultivar M7 was more resistant to ozone or sulfur dioxide than M9 and S201.

The effects of sulfur dioxide on buffering capacity, chlorophyll content, stomatal conductance, mineral composition and leaf injury of winter wheat ( Triticum aestivum , cv. Yecora Rojo) were studied. Plants were exposed to sulfur dioxide (0, 79, 183, and 393 μg m −3 ) in open-top chambers. Exposures were conducted in Riverside, California, during the coolest part of the year when the plants are believed to be more sensitive to sulfur dioxide than during the rest of the year. Physiological measurements, injury rating and collection of leaf material for chemical analysis were carried out after 22 days of exposure. The results of these measurements were compared with yield data from the final harvest which took place after 118 days of exposure. Elevated SO 2 concentrations caused decrease of buffering capacity, increase of total sulfur content and increase of injury of wheat leaves. These changes correlated significantly with reduction of total seed weight and weight of 100 wheat seeds at the final harvest. Stomatal conductance to water vapor, chlorophyll content and two leaf mineral concentrations (calcium, potassium) were not significantly affected by sulphur dioxide exposure. The results of this study indicated that buffering capacity, total sulfur content and injury of leaves could be used as early indicators of SO 2 stress in wheat and its subsequent yield losses.

Forty-seven species of annual plants from the Mojave Desert were grown in pots and exposed in open-top field chambers located at Riverside, California to test their relative sensitivity to SO/sub 2/ and O/sub 3/. Exposures were 8 h/day for four or five days at 0, 0.05, 0.1, 0.2, 0.3 and 0.4 ppm O/sub 3/ or 0, 0.2, 0.5, 0.6, 0.8, 1.0 and 1.5 ppm SO/sub 2/. Species differed widely in their response to the pollutants. Three species, Camissonia claviformis, Camissonia hirtella and Cryptantha nevadensis, were quite sensitive to both pollutants, exhibiting leaf injury when exposed to 0.1 ppm O/sub 3/ or 0.2 ppm SO/sub 2/. Two species: Festuca octoflora and Lepidium lasiocarpum were tolerant to both pollutants, exhibiting no leaf injury with concentrations of 0.3 ppm O/sub 3/ or 1.5 ppm SO/sub 2/. The other species were intermediate in sensitivity, with O/sub 3/ sensitivity not always corresponding to SO/sub 2/ sensitivity. Total sulfur concentration analysis indicated that for 8 of 11 species tested, plants exposed to 0.2 ppm SO/sub 2/ had a higher sulfur concentration than nonexposed plants. Baileya pleniradiata and Perityle emoryi had the greatest increases in sulfur concentration for exposed versus control plants. To test for effects ofmore » the environmental and exposure system on plant sensitivity, 29 of the species exposed in the open-top chambers were grown in the ground and exposed with a modified chamberless zonal air pollution (ZAP) system to SO/sub 2/ in the Mojave Desert area near Daggett, California. Exposures were for a total of 37 h over six days to 0, 0.4, 0.8 and 1.0 ppm SO/sub 2/ with exposures only during periods with due west winds. Most of the species were not injured with any of the SO/sub 2/ exposure concentrations used with the ZAP system; only Camissonia claviformis showed injury at 0.8 ppm SO/sub 2/ and Oenothera californica exhibited injury at 1.0 ppm SO/sub 2/.« less