Ozone and air particulate measurements in mountain forest sites

Dell'Era, R.; Brambilla, Elia; Ballarin-Denti, A.

doi:10.1016/s0045-6535(97)10176-x

Cited by 8 publications

(6 citation statements)

References 5 publications

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“…Based on previous work, it was expected that only the His residue would gain three oxygen atoms during ozonolysis; however, the CID and SID data suggest otherwise ( Figure 3a and Table 2). Because His is the sixth residue from the N-terminus, b 6 to b 8 and y 3 to y 8 are expected to be shifted by ϩ48 Da. In addition, His immonium ions and His-containing internal fragments are expected to be shifted by ϩ48 Da.…”

Section: Esi-msms-cid and Sidmentioning

confidence: 99%

Peptide ozonolysis: Product structures and relative reactivities for oxidation of tyrosine and histidine residues

Lloyd

Spraggins

Johnston

et al. 2006

J. Am. Soc. Mass Spectrom.

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Angiotensin II (DRVYIHPF) and two analogs, (DRVYIAPA and DRVAIHPA), were used as model systems to study the ozonolysis of peptides containing tyrosine and histidine residues. The ESI mass spectrum of angiotensin II following exposure to ozone showed the formation of adducts containing one, three, and four oxygen atoms. CID and SID spectra of these adducts were consistent with formation of Tyr ϩ O and His ϩ 3O as expected from previous work with amino acids. However, several fragment ions observed in the CID and SID spectra suggested formation of a rather unexpected adduct, Tyr ϩ 3O, and a small amount of the Phe ϩ O adduct. These findings were confirmed by examining two angiotensin analogs. Exposure of DRVYIAPA to ozone resulted in the addition of either one or three oxygen atoms on Tyr, while DRVAIHPA showed only the addition of three oxygen atoms-all on His. Other noteworthy minor oxidation products were observed from these analogs including Tyr ϩ 34 Da, His ϩ 5 Da, His ϩ 34 Da, and His ϩ 82 Da. The reaction rates of the peptides with ozone were found to be similar: second-order rate coefficients are 274 Ϯ 3, 379 Ϯ 6, and 439 Ϯ 34 M Ϫ1 s Ϫ1 for DRVYIAPA, DRVAIHPA, and angiotensin II, respectively. The relative rates indicate (1) an isolated His residue has a slightly greater ozone reactivity than an isolated Tyr residue, and (2) the reaction rates of isolated residues are not additive when both residues are present in the same

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Section: Esi-msms-cid and Sidmentioning

confidence: 99%

Peptide ozonolysis: Product structures and relative reactivities for oxidation of tyrosine and histidine residues

Lloyd

Spraggins

Johnston

et al. 2006

J. Am. Soc. Mass Spectrom.

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“…While other phytotoxic pollutants like SO 2 or NO x exhibited extremely low concentrations (2-5 and 3 ppb, respectively, on average) [4,7,8,36,37], ozone showed mean seasonal concentrations of 42 and 71 ppb during the 5-year campaign, respectively, in Val Masino and Val Gerola. In the latter, the most damaged area, ozone hourly peaks reached a maximum value of 160 ppb in some days during 1996, while in Val Masino, in the same year, they reached 110 ppb.…”

Section: Resultsmentioning

confidence: 99%

“…Tropospheric ozone has been representing one of the major stress factors for forest ecosystems in both North America and Europe [1,2] due to its harmful phytotoxic effects. In mountain areas, where most forests are located, ozone monitoring is often critical, due to logistic factors and the spatial density of sampling required by the morphological complexity of the territory [3,4]. In these cases, the use of passive samplers represents a valid alternative to continuous analysers, which are more expensive and demanding in terms of power supply, temperature control, maintenance, calibration, and cost [5,6].…”

Section: Introductionmentioning

confidence: 99%

Techniques of Ozone Monitoring in a Mountain Forest Region: Passive and Continuous Sampling, Vertical and Canopy Profiles

Gerosa

Mazzali

Ballarin-Denti

2001

The Scientific World JOURNAL

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Ozone is the most harmful air pollutant for plant ecosystems in the Mediterranean and Alpine areas due to its biological and economic damage to crops and forests. In order to evaluate the relation between ozone exposure and vegetation injury under on-field conditions, suitable ozone monitoring techniques were investi-gated. In the framework of a 5-year research project aimed at ozone risk assessment on forests, both continuous analysers and passive samplers were employed during the summer seasons (1994—1998) in different sites of a wide mountain region (80 x 40 km2) on the southern slope of the European Alps. Continuous analysers allowed the recording of ozone hourly concentration means necessary both to calculate specific exposure indexes (such as AOT, SUM, W126) and to record daily time-courses. Passive samplers, even though supplied only weekly mean concentration values, made it possible to estimate the altitude concentration gradient useful to correct the altitude dependence of ozone concentrations to be inserted into exposure indexes. In-canopy ozone profiles were also determined by placing passive samplers at different heights inside the forest canopy. Vertical ozone soundings by means of tethered balloons (kytoons) allowed the measurement of the vertical concentration gradient above the forest canopy. They also revealed ozone reservoirs aloft and were useful to explain the ozone advection dynamic in mountain slopes where ground measurement proved to be inadequate. An intercomparison between passive (PASSAM, CH) and continuous measurements highlighted the necessity to accurately standardize all the exposure operations, particularly the pre- and postexposure conservation at cold temperature to avoid dye (DPE) activity. Advantages and disadvantages from each mentioned technique are discussed.

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“…Thanks to the monitoring campaigns performed in previous years [8,15], a series of data sets dating back to 1998 and earlier were available as continuous hourly measurements from analysers and from passive samplers at the same sites. These values have been used to improve the AOT40 assessment.…”

Section: Aot40 Mapsmentioning

confidence: 99%

“…Furthermore, data collected over several years through monitoring campaigns by passive samplers were available [8]. Besides weekly concentration data provided by passive samplers, hourly concentration values were also available from continuous analysers placed in mobile labs [9] in the same sites and for long periods of time.…”

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confidence: 99%

Ozone Risk Assessment and Mapping in the Alps Based on Data from Passive Samplers

Mazzali¹,

Angelino

Gerosa

et al. 2002

The Scientific World JOURNAL

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Passive samplers (diffusion tubes with organic reagent, produced by Passam of Switzerland) were used in a sampling campaign for the detection of weekly mean ozone concentrations in 15 sites over a domain of 80 × × × × 40 km on the southern side of the European Alps from May to August 1998. The area is characterized by vast natural terrain of complex topography, with conifer and broadleaf forests. It is difficult to access and monitor air quality there with continuous analysers. By applying geostatistical techniques (ordinary kriging), and correcting the interpolated ozone concentrations according to the altitude of each single grid cell (2 × × × × 2 km), maps of weekly ozone concentrations were produced. The weekly ozone data were used to assess daily and hourly data by means of an iterative procedure based on a functional dependence of ozone concentrations both on altitude and on the time of day. This allowed the estimation of values with an exposure index such as AOT40 (accumulated exposure over the threshold of 40 ppb) in all 800 cells of the domain. This also allowed the mapping of risk assessment related to the effects of ozone on the regional forest vegetation. Results obtained show values that exceed the exposure standards adopted in the Kuopio protocol (1996). Excess exposure values also match values calculated over a wider territorial domain by using hourly data on ozone concentration derived from continuous automatic analysers.KEY WORDS: ozone, risk assessment, Alps, forests, passive samplers, exposure indices, AOT40, geostatistics DOMAINS: atmospheric systems, ecosystems and communities, environmental toxicology, environmental technology, environmental management and policy, ecosystems management, environmental monitoring, environmental modelling, information management Mazzali et al.: Ozone Risk Assessment by Passive Sampling TheScientificWorldJOURNAL (2002) 2, 1023-1035 1024 INTRODUCTIONThe growing stress of high ozone levels in alpine forest ecosystems faces us with the need to perform risk assessment for specific receptors to allow for the protection of the ecological, economic, and aesthetic values of vegetation. During the assessment of dose-response relationship of vegetation to ozone exposure, investigators concentrated on the use of indices to quantify the exposure. Several studies have dealt with both definition and assessment of these indices, taking into account the most harmful pollution levels for vegetation [1,2]. The most frequently used exposure indices attribute different weights to high and low ozone concentrations; these indices include SUM x (sum of the hourly concentrations beyond the x threshold), AOT x (sum of the differences between hourly concentrations and the x threshold), W y (sum of the hourly concentrations weighted by means of sigma functions indicated by the value of y), and AL y (sum of the hourly concentrations weighted by means of allometric functions indicated by the value of y) [3].According to some indices, literature supplies potential damage thresholds (crit...

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Ozone and air particulate measurements in mountain forest sites

Cited by 8 publications

References 5 publications

Peptide ozonolysis: Product structures and relative reactivities for oxidation of tyrosine and histidine residues

Peptide ozonolysis: Product structures and relative reactivities for oxidation of tyrosine and histidine residues

Techniques of Ozone Monitoring in a Mountain Forest Region: Passive and Continuous Sampling, Vertical and Canopy Profiles

Ozone Risk Assessment and Mapping in the Alps Based on Data from Passive Samplers

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