Charcoal Filter Research Articles

Efficiency of Bark, Activated Charcoal, Foam and Sand Filters in Reducing Pollutants from Greywater

Greywater is a potential resource of water that can be improved to meet the quality needed for irrigation. This study evaluated the performance of bark, activated charcoal, polyurethane foam and sand filters in removing biochemical oxygen demand (BOD5), surfactants, phosphorus, nitrogen and microbial indicators from greywater during start-up and steady state. In column experiments, 0.6 m high filters (diameter 20 cm) were fed for 113 days with artificial greywater at a hydraulic loading rate of 0.032 m3 m−2 day−1 and an organic loading rate of 0.014 kg BOD5 m−2 day−1. Bark and activated charcoal efficiently reduced the concentrations of organics (BOD5), surfactants (methylene blue active substances—MBAS), total phosphorus (Tot-P) and total thermotolerant coliform numbers, while sand and foam were less efficient. Bark, activated charcoal, foam and sand reduced influent BOD5 by 98, 97, 37 and 75 %; MBAS by >99, >99, 73 and 96 %; Tot-P by 97, 91, 36 and 78 %; and total nitrogen by 19, 98, 13 and 5 %, respectively. BOD5 and MBAS were efficiently reduced directly from start-up by bark and activated charcoal, while foam needed 30 days to achieve about 50 % reduction in BOD5. Bark was the most efficient filter in reducing thermotolerant faecal coliforms (2.4 log10), while foam achieved the lowest reduction (0.5 log10). Overall, bark and activated charcoal filters appeared to be the most suitable filters for improving greywater quality to reach irrigation quality in terms of organic matter reduction. Performance of these filters under higher and fluctuating loadings and the long-term sustainability of the filter materials need further investigation.

Determinants of High Pesticide Exposure Events in the Agricultural Health Cohort Study from Enrollment (1993-1997) through Phase II (1999-2003)

We conducted an analysis of the determinants of high pesticide exposure events (HPEEs), which are defined as self-reported incidents of high exposure to pesticides, fertilizers, or other chemicals in the Agricultural Health Study, a cohort of private applicators and their spouses residing in North Carolina or Iowa, and commercial applicators residing in Iowa. We examined the risk of HPEEs occurring between enrollment (phase 1: 1993-1997) and follow-up (phase II: 1999-2003) among participants who completed the phase II questionnaire (n=43,149) by calculating hazard rate ratios and 95% confidence intervals using Cox proportional-hazard regression. During the followup period, 1,582 HPEEs were reported (3.8%). HPEE risk was significantly higher among Iowa residents, younger participants, those with a hearing deficit, a risk-taking personality, and an HPEE prior to enrollment. Among private applicators (n=30,102), larger farm size, higher frequency and duration of pesticide use, spraying pesticides with open cab windows, using a tractor cab without a charcoal filter, repairing spray equipment, wearing work clothing more than two days without changing, not removing work boots before entering the home, and storing pesticides in the home were associated with significantly higher HPEE risk. Among commercial applicators (n=2326), higher frequency of pesticide use was associated with a significantly higher HPEE risk. Among spouses (n=10,721), higher frequency of pesticide use, using an application vehicle with a cab, and storing pesticides in the home were associated with a significantly higher HPEE risk. Our findings indicate that HPEEs were associated with several modifiable pesticide handling procedures that can be targeted in safety training and education.

Considerations for the design and technical setup of a human whole-body exposure chamber

Exposures to air contaminants, such as chemical vapors and particulate matter, pose important health hazards at workplaces. Short-term experimental exposures to chemical vapors and particles in humans are a promising attempt to investigate acute effects of such hazards. However, a significant challenge in this field is the determination of effects of co-exposures to more than one chemical or mixtures of chemical vapors and/or particles. To overcome such a challenge, studies have to be conducted under standardized exposure characterization and real time measurements, if possible. A new exposure laboratory (ExpoLab) was installed at IPA, combining sophisticated engineering designs with new analytical techniques, to fulfill these requirements. Low-dose as well as high-dose exposure scenarios are achieved by means of a calibration-gas-generator. Exposure monitoring can be carried out with a high performance real time mass spectrometer and other suitable analyzers (e.g. gas chromatograph). Numerous automated security facilities guarantee the physical integrity of the volunteers, and the waste atmosphere is removed using either charcoal filtration or catalytic post-combustion. Measurements of sulfur hexafluoride, carbon dioxide, aniline and carbon black are presented to demonstrate the performance of the exposure unit with respect to the temporal and spatial stability of generated atmospheres. The variations of generated contents in the atmospheres at steady state are slightly higher than the measurement precision of the analyzers (the typical standard deviation of generated atmospheres is < 2%). The technical components of ExpoLab and its monitoring systems ensure high quality standards in validity and reliability of generating and measuring exposure atmospheres.

Charcoal filter paper improves the viability of cryopreserved filamentous ectomycorrhizal and saprotrophic Basidiomycota and Ascomycota

We assessed viability of 18 strains of filamentous ectomycorrhizal and saprotrophic basid-iomycetes and ascomycetes after cryopreservation with a novel technique based on charcoal filter paper strips (CFS). The results indicate that axenic fungal cultures grown on CFS recovered from freezing within a few days, even though none survived cryopreservation by the conventional straw method. Fungal growth on CFS was more vigorous, with morphological differentiations such as rhizomorphs and an increased amount of aerial mycelia compared to the unamended culture media. Accordingly CFS allows the cryopreservation of a wide range of rare and important ectomycorrhizal and saprotrophic fungi, which hitherto were difficult to revive from liquid nitrogen storage with the conventional and widely applied straw technique.

Simultaneous removal of formaldehyde and benzene in indoor air with a combination of sorption- and decomposition-type air filters

Urgent measures for indoor air pollution caused by volatile organic compounds are required in urban areas of China. Considering indoor air concentration levels and hazardous properties, formaldehyde and benzene should be given priority for pollution control in China. The authors proposed the use of air-cleaning devices, including stand-alone room air cleaners and in-duct devices. This study aimed to find the best combination of sorption and decomposition filters for the simultaneous removal of formaldehyde and benzene, employing four types of air filter units: an activated charcoal filter (ACF), an ACF impregnated with a trapping agent for acidic gases (ACID), a MnO2 filter (MDF) for oxidative decomposition of formaldehyde at room temperature and a photocatalyst filter (PHOTO) coupled with a parallel beam ultraviolet (UV) irradiation device. The performance of the combined systems under air flow rates of 35–165 m3 h−1 was evaluated in a test chamber (2 m3) with a constant gas generation system. The experimental results and data analysis using a kinetic approach showed the combined system of ACF, PHOTO and MDF significantly reduced both concentrations of formaldehyde and benzene in air without any unpleasant odours caused by the UV-induced photocatalytic reaction. The system was then evaluated in a full-size laboratory (22 m3). This test proved the practical performance of the system even at full scale, and also suggested that the filters should be arranged in the order of PHOTO/ACF/MDF from upstream to downstream. The proposed system has the potential of being used for improving indoor air quality of houses and buildings in China.

Causes Analysis and Treatment Measures for Excess SiO&lt;sub&gt;2&lt;/sub&gt; Content in a 300MW Unit Boiler Water

According to the characteristics of silicon in water, analysis is implemented for the excess SiO2 content in a 300MW unit boiler water. Serious excess SiO2 content in the economizer inlet water and boiler water is caused by high-pressure heater leakage. In addition, SiO2 content increases with the raising feedwater temperature, because colloidal silicon solubility increases with the raising feedwater temperature. Colloidal silicon in water is induced by condenser tiny leakage. High-pressure heater plugging must be handled. Improving activated charcoal filters washing and boiler blow-off frequency can be used to reduce the impact of colloidal silicon on boiler and ensure safe operation of the boiler

Optimal engineering of air purification systems for an IVF laboratory will minimize volatile organic compounds and airborne respirable particulates to almost undetectable levels

Strict control of ambient lab air quality is critical for optimal IVF outcome. Volatile organic compounds (VOCs) and airborne respirable particulates (ARPs) are eliminated with activated charcoal and high efficiency particulate air (HEPA) filtration. HEPA filtration removes particulates ≥0.3μm through diffusion and interception while activated carbon utilizes chemical absorption of VOCs. We installed heating/ventilation/air-conditioning (HVAC) systems in 3 newly constructed IVF/operative suites.

Homing Pigeons Only Navigate in Air with Intact Environmental Odours: A Test of the Olfactory Activation Hypothesis with GPS Data Loggers

A large body of evidence has shown that anosmic pigeons are impaired in their navigation. However, the role of odours in navigation is still subject to debate. While according to the olfactory navigation hypothesis homing pigeons possess a navigational map based on the distribution of environmental odours, the olfactory activation hypothesis proposes that odour perception is only needed to activate a navigational mechanism based on cues of another nature. Here we tested experimentally whether the perception of artificial odours is sufficient to allow pigeons to navigate, as expected from the olfactory activation hypothesis. We transported three groups of pigeons in air-tight containers to release sites 53 and 61 km from home in three different olfactory conditions. The Control group received natural environmental air; both the Pure Air and the Artificial Odour groups received pure air filtered through an active charcoal filter. Only the Artificial Odour group received additional puffs of artificial odours until release. We then released pigeons while recording their tracks with 1 Hz GPS data loggers. We also followed non-homing pigeons using an aerial data readout to a Cessna plane, allowing, for the first time, the tracking of non-homing homing pigeons. Within the first hour after release, the pigeons in both the Artificial Odour and the Pure Air group (receiving no environmental odours) showed impaired navigational performances at each release site. Our data provide evidence against an activation role of odours in navigation, and document that pigeons only navigate well when they perceive environmental odours.

P2-172 Adverse health events during occupational exposure to pesticides, in Cordoba, Argentina. An estimation of its impact on agricultural applicators health

The use of pesticides undeniably comes with some risks. It is understood that people who work with pesticides typically have much higher exposure than general public. The present work evaluated...

New Device Simplifies Workstation Preparation for Malignant Hyperthermia-susceptible Patients

Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania. feldmanj@email.chop.eduI read with interest the review article by Kim and Nemergut entitled “Preparation of Modern Anesthesia Workstations for Malignant Hyperthermia-susceptible Patients.”1The authors are to be congratulated on this comprehensive review describing the challenges to preparing a modern anesthesia machine for use with malignant hyperthermia (MH)-susceptible patients. Indeed, their review of the literature suggests that a straightforward method of preparing the machine that can be applied to all workstations has not been determined. Further, the current information on the Malignant Hyperthermia Association of the United States website does not provide practical guidance to prepare all types of anesthesia machines.*For the anesthesia practitioner, reading the available literature does not provide a clear approach to be used in practice.A new device promises to provide an easy method for preparing any anesthesia workstation for MH-susceptible patients in just a few minutes. The Vapor-Clean device (Dynasthetics Inc., Salt Lake City, UT) consists of charcoal filters designed to be placed between the anesthesia machine and the inspiratory and expiratory limbs of the breathing circuit. The rationale for this approach is sound and based on the well-known property of activated charcoal to absorb potent anesthetic vapors that can trigger MH. If a clean breathing circuit is used and the Vapor-Clean device is in place, anesthetic vapor contaminating the internal components of the anesthesia workstation is prevented from reaching the patient. Previous studies have documented the utility of activated charcoal for preparing the anesthesia machine but to date, a convenient device designed and approved by the Food and Drug Administration for this purpose has not existed.2,3A study of the Vapor-Clean has demonstrated that the concentration of anesthetic agents (isoflurane, sevoflurane, and desflurane) in the breathing circuit can immediately be reduced to less than 5 ppm immediately upon placing the device in the circuit.4The concentration of anesthetic vapor that protects the susceptible patient from an MH reaction has never been determined with certainty, but concentrations less than 5 ppm are generally considered acceptable, and the results documented in the abstract exceed that goal.With the introduction of the Vapor-Clean device, a simple approach to rapidly preparing any anesthesia workstation for the MH susceptible patient now exists. Additional studies will likely document the universal utility of this device for all workstations and anesthetic vapors, but given the simplicity of the device and the well-known properties of activated charcoal, I submit that there is sufficient evidence to adopt this device into clinical practice. The manufacturer provides a clear protocol for using the device that can be easily implemented by any practitioner. With the advent of the Vapor-Clean device, it would seem that the challenge of protecting MH susceptible patients from trace amounts of anesthetic vapor has been solved.Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania. feldmanj@email.chop.edu

Activated Charcoal Effectively Removes Inhaled Anesthetics from Modern Anesthesia Machines

If a malignant hyperthermia-susceptible patient is to receive an anesthetic, an anesthesia machine that has been used previously to deliver volatile anesthetics should be flushed with a high fresh gas flow. Conflicting results from previous studies recommend flush times that vary from 10 to 104 minutes. In a previously proposed alternative decontamination technique, other investigators placed an activated charcoal filter in the inspired limb of the breathing circuit. We placed activated charcoal filters on both the inspired and expired limbs of several contaminated anesthesia machines and measured the time needed to flush the machine so that the delivered concentrations of isoflurane, sevoflurane, and desflurane would be <5 parts per million (ppm). We next simulated the case for which malignant hyperthermia is diagnosed 90 minutes after induction of anesthesia and measured how well activated charcoal filters limit further exposure. Activated charcoal filters decrease the concentration of volatile anesthetic delivered by a contaminated machine to an acceptable level in <2 minutes. The concentrations remained well below 5 ppm for at least 60 minutes. When malignant hyperthermia is diagnosed after induction of anesthesia, we found that with charcoal filters in place, the current anesthesia machine may be used for at least 67 minutes before the inspired concentration exceeds 5 ppm. Activated charcoal filters provide an alternative approach to the 10 to 104 minutes of flushing that are normally required to prepare a machine that has been used previously to deliver a volatile anesthetic.

Flushing induction chambers used for rodent anesthesia to reduce waste anesthetic gas

Anesthetic induction chambers used for medical research are a substantial source of waste anesthetic gas (WAG). Ideally, any generated waste gas should be actively vented away from personnel operating the chamber by either a ventilated hood or snorkel. Unfortunately, the ideal environment for anesthetizing rodents is not always available. In an effort to create a safer environment, the authors designed a system to reduce WAG. This system is portable, can be adapted to different precision vaporizing anesthetic systems and fits in a variety of physical locations. The system flushes anesthetic gas out of an induction chamber before operators open the chamber. To ensure that the system was adequately flushing the anesthetic gas, the authors measured WAG concentration in the environment above the induction chamber and directly behind the vent of an activated charcoal filter. They also compared the efficiency of the filters in vertical and horizontal positions. Finally, they measured the recovery time for mice and rats after flushing the anesthetic gas from an induction chamber. The results show that flushing the induction chamber was an inexpensive and effective method for reducing WAG accumulation in the air surrounding the chamber.

Exposure to Technologists from Preparing and Administering Therapeutic 131I: How Frequently Should We Bioassay?

It is common for nuclear medicine technologists to perform procedures involving the preparation and administration of therapeutic levels of (131)I-sodium iodide. This small study looked at the question of how much internal exposure a technologist receives, on average, while preparing and administering a therapeutic dose of (131)I. The study estimated technologists' intake of airborne (131)I by measuring air concentrations in their breathing zone during therapeutic procedures using (131)I capsules. The measurement was made by determining the radioactivity collected on a charcoal filter contained within a personal air sampler. The radioactivity captured by the charcoal filter was assessed in a well counter. Given these data, we were able to estimate the average (131)I intake of a technologist working in a general nuclear medicine department over a period of 1 y: about 19.2 kBq (0.52 μCi). The NRC requirement is to monitor workers who could inhale or ingest more than 185 kBq (5 μCi) of (131)I in 1 y. The results of this small study suggest internal exposure rates that are well below the annual Nuclear Regulatory Commission trigger limits for individual bioassay.

Effect of Charcoal Filter on the Emergence from Sevoflurane Anesthesia in a Semi-Closed Rebreathing Circuit

PurposeA charcoal filter attached within the anesthetic circuit has been shown to efficiently adsorb halothane or isoflurane, thus hastening anesthetic recovery in low or minimal flow system. This study was intended to demonstrate whether the charcoal filter enhances the recovery time from sevoflurane anesthesia using a semi-closed circuit system.Materials and MethodsThirty healthy patients scheduled for elective surgery under sevoflurane anesthesia were randomly assigned to the charcoal filter or control group. Upon completion of surgery, the end-tidal concentration of sevoflurane was maintained at 2.0 vol%. A charcoal filter was attached to the expiratory limb of the breathing circuit of charcoal filter group subjects. After sevoflurane was discontinued, ventilation was controlled with the same minute volume as the intra-operative period at a fresh gas flow rate of 5 L·min-1 with 100% O2. The elimination kinetics of sevoflurane from end-tidal concentration, Bispectral index and times of eye opening and extubation were obtained.ResultsThe exponential time constant (τ) of alveolar sevoflurane concentration in the charcoal filter group was significantly shorter than that in the control group (1.7±0.5 vs. 2.5±1.1 min, p=0.008). The charcoal filter hastened rapid eye opening (11.1±3.8 vs. 14.8±3.0 min, p=0.007) and extubation (11.9±3.9 vs. 15.3±3.2 min, p=0.014), compared to the control group.ConclusionA charcoal filter enhances the recovery from sevoflurane anesthesia with a semi-closed rebreathing circuit.

The Effect of Cigarette Design on the Content of Phenols in Mainstream Tobacco Smoke

Abstract The influence of cigarette design on the content of phenols in mainstream tobacco smoke was studied. The most abundant phenols - catechol, hydroquinone, phenol, o-, m-, and p-cresol, and resorcinol - were determined by HPLC with fluorescence detection. Hydroquinone and catechol made the most significant contribution to the total content of phenols with maximum values of 135.0 µg/cig and 95.7 µg/cig, respectively. The highest total content of phenols (330.9 µg/cig) was measured in the smoke of a Virginia tobacco cigarette. The total content of phenols (µg/cig) in cigarette mainstream smoke decreased linearly with increased filter ventilation, R2 = 0.9536. The results obtained indicate that filtration and ventilation can strongly influence the mainstream tobacco smoke content of phenol and its less polar derivatives, o-, m-, and p-cresol, which were reduced by up to 85%. Hydroquinone and catechol are less affected and only cigarettes with the special “recessed charcoal filter system” and cigarettes with filter ventilation over 50% showed significant reductions. On a per mg ‘tar’ basis the largest contributor to phenols in cigarette mainstream smoke was the selection of the tobacco type. The use of any standard commercial filter on an unfiltered cigarette can substantially reduce the yield of phenols in cigarette mainstream smoke. The use of special filters (e.g., the “recessed charcoal filter system”) or high levels of cigarette ventilation does not reduce the amount of phenols in tobacco smoke considerably when normalized on a per mg ‘tar’ basis.

Two-year follow-up biomonitoring pilot study of residents’ and controls’ PFC plasma levels after PFOA reduction in public water system in Arnsberg, Germany

Residents in Arnsberg, Germany, had been supplied by drinking water contaminated with perfluorooctanoate (PFOA). Biomonitoring data from 2006 evidenced that plasma PFOA concentrations of residents from Arnsberg were 4.5-8.3 times higher than those in reference groups. The introduction of charcoal filtration in July 2006 distinctly reduced PFOA concentrations in drinking water. Our one-year follow-up study showed a 10-20% reduction of PFOA plasma levels in residents from Arnsberg. Here we report the first results of the two-year follow-up study Arnsberg 2008. Additionally, the results of the two-year follow-up examination of the reference group are included. Paired plasma samples of 138 study participants (45 children, 46 mothers and 47 men) collected in 2006 and 2008 were considered in the statistical analyses. Within the two years plasma concentrations of PFOA, perfluorooctanesulfonate (PFOS) and perfluorohexanesulfonate (PFHxS) decreased in residents from Arnsberg and in control groups. The geometric means of PFOA plasma levels declined by 39% (children and mothers) and 26% (men) in Arnsberg and by 13-15% in the corresponding subgroups from the reference areas. For the population from Arnsberg a geometric mean plasma PFOA half-life of 3.26 years (range 1.03-14.67 years) was calculated. Our results confirm an ongoing reduction of the PFOA load in residents from Arnsberg. The decline of PFC levels in plasma of participants from the reference areas reflects the general decrease of human PFC exposure during the very recent years.

Activated charcoal filter effectively reduces p-benzosemiquinone from the mainstream cigarette smoke and prevents emphysema

In this paper, we have made a comparative evaluation of the cytotoxicity and pathophysiological effects of mainstream smoke from cellulose acetate (CA)-filtered cigarettes with that of charcoal-filtered cigarettes developed in our laboratory. Previously, we had demonstrated that the mainstream smoke from an Indian CA-filtered commercial cigarette contains p-benzosemiquinone (p-BSQ), a major, highly toxic, long-lived water-soluble radical. Here, we have examined 16 brands of different CA-filtered cigarettes including Kentucky research cigarettes, and observed that mainstream smoke from all the cigarettes contains substantial amounts of p-BSQ (100-200 μg/cigarette). We also show that when the CA filter is replaced by a charcoal filter, the amount of p-BSQ in the mainstream smoke is reduced by 73-80%, which is accompanied by a reduction of carbonyl formation in bovine serum albumin to the extent of 70- 90%. The charcoal filter also prevented cytotoxicity in A549 cells as evidenced by MTT assay, apoptosis as evidenced by FACS analysis, TUNEL assay, overexpression of Bax, activation of p53 and caspase 3, as well as emphysematous lung damage in a guinea pig model as seen by histology and morphometric analysis. The results indicate that the charcoal filter developed in our laboratory may protect smokers from cigarette smoke-induced cytotoxity, protein modification, apoptosis and emphysema.

Different Types and Settings of Kitchen Canopy Hoods and Particulate Exposure Conditions during Pan-frying of Beefsteak

The aim of this study was to compare four different kinds of canopy hoods in common use in private Norwegian households, in regard to their ability to protect the cook from exposure to particles from cooking fumes and to reduce the spreading of fume particles in the kitchen. The hoods were tested during pan-frying of beefsteak under different combinations of the following parameters: medium or maximum flow rate in the hood, two different heights above the stove and three different locations in the kitchen. The mass concentration of total particles in the breathing zone of the cook and the number concentration of particles in the size interval 0.3—0.5 μm in the kitchen was measured. To achieve the best possible effect of a kitchen canopy hood under the conditions described, it is best to mount it in a corner with a 60 cm distance to the stove and run it on the maximum flow rate. Also, it is best to install hoods that extract the polluted air out of the house rather than recycling it through a charcoal filter.

Charcoal Hemoperfusion in the Treatment of Levothyroxine Intoxication

Levothyroxine (l-thyroxine) intoxication may arise from intentional or accidental ingestion of excessive doses of the hormone and may cause symptoms equivalent to thyroid storm. We report a case of massive accidental l-thyroxine intoxication resulting from an error in the preparation of capsules to treat goiter. A 61-year-old woman was admitted showing high levels of thyroid hormones, with serum-free l-thyroxine level of 955.90 nmol/L (74.1 ng/mL) (normal values: 11.61-27.09 nmol/L or 0.9-2.1 ng/mL). It was discovered that she had ingested 50 mg instead of 50 microg/day of l-thyroxine during 9 days. Following charcoal hemoperfusion, the levels of total thyroxine, serum-free l-thyroxine, and triiodothyronine declined dramatically, with a reproducible pattern of reduction in hormone levels observed after each of the three sessions. The patient recovered from her stuporous mental state, atrial fibrillation, and acute respiratory failure. The use of hemoperfusion with a charcoal filter appears to be a very important therapeutic tool for the treatment of acute and severe forms of thyrotoxicosis due to l-thyroxine intoxication.

Early Events inPopulusHybrid andFagus sylvaticaLeaves Exposed to Ozone

This paper aims to investigate early responses to ozone in leaves of Fagus sylvatica (beech) and Populus maximowiczii x Populus berolinensis (poplar). The experimental setup consisted of four open-air (OA) plots, four charcoal-filtered (CF) open-top chambers (OTCs), and four nonfiltered (NF) OTCs. Qualitative and quantitative analyses were carried out on nonsymptomatic (CF) and symptomatic (NF and OA) leaves of both species. Qualitative analyses were performed applying microscopic techniques: Evans blue staining for detection of cell viability, CeCl3 staining of transmission electron microscope (TEM) samples to detect the accumulation of H2O2, and multispectral fluorescence microimaging and microspectrofluorometry to investigate the accumulation of fluorescent phenolic compounds in the walls of the damaged cells. Quantitative analyses consisted of the analysis of the chlorophyll a fluorescence transients (fast kinetics). The early responses to ozone were demonstrated by the Evans blue and CeCl3 staining techniques that provided evidence of plant responses in both species 1 month before foliar symptoms became visible. The fluorescence transients analysis, too, demonstrated the breakdown of the oxygen evolving system and the inactivation of the end receptors of electrons at a very early stage, both in poplar and in beech. The accumulation of phenolic compounds in the cell walls, on the other hand, was a species-specific response detected in poplar, but not in beech. Evans blue and CeCl3 staining, as well as the multispectral fluorescence microimaging and microspectrofluorometry, can be used to support the field diagnosis of ozone injury, whereas the fast kinetics of chlorophyll fluorescence provides evidence of early physiological responses.