Organic composition of fogwater in the Texas–Louisiana gulf coast corridor

Fogwater and air samples were collected in Baton Rouge between November 2004–February 2005 and during February 2006 at Houston. Organic compounds present in the fog samples were detected, quantified and then grouped into different compound classes based on molecular size, solubility and polarity using gas chromatography/mass spectrometry, high performance liquid chromatography with diode array detection and ion chromatography. Organic compounds were grouped as n-alkanes, aromatics and polycyclic aromatics, carbonyls, alcohols, amides and esters. Organic compounds in fog and air samples in Houston indicated clear urban/industrial anthropogenic origin, while compounds detected in Baton Rouge fog and air samples showed a mix of both agricultural and urban/industrial anthropogenic inputs. Among the various polycyclic aromatic compounds detected, the total concentration of naphthalene and its derivatives was 2.8 μg m^?3 in Houston and 0.08 μg m^?3 in Baton Rouge air. Analysis of concentrations of organic compounds pre- and post- fog revealed that compounds with low vapor pressure had higher scavenging efficiency in fog sampled at the two locations. Concentrations of organic compounds in fog samples were higher than those predicted by conventional air-water Henry's law equilibrium. Observed higher concentrations in the aqueous phase were modeled accounting for surface adsorption and accumulation of gas phase species and the presence of humic-like substances in fogwater.     

Contribution of transboundary air pollution to ionic concentrations in fog in the Kinki Region of Japan

To estimate the contribution of transboundary transported air pollutants from other Asian countries to Japan in ionic concentrations in fog water in March 2005, the Community Multiscale Air Quality (CMAQ) modeling system was utilized with meteorological fields produced by the 5th generation Mesoscale Model (MM5). For meteorological predictions, the model well reproduced the surface meteorological variables, particularly temperature and humidity, and generally captured fog occurrence. For chemical predictions, most of the model-predicted monthly mean concentrations were approximately within a factor of 2 of the observations, indicating that the model well simulated the long-range atmospheric transport from the Asian Continent to Japan. For SO₄^2?, NO₃^? and NH₄⁺, the contribution rates of the transboundary air pollution in the Kinki Region of Japan ranged from 69 to 82% for aerosols, from 47 to 87% for ionic concentrations in rain, and from 55 to 79% for ionic concentrations in fog. The study found that the transboundary air pollution also affected ionic concentrations in fog as well as aerosol concentrations and ionic concentrations in rain.     

Biogenic C5 VOCs: release from leaves after freeze–thaw wounding and occurrence in air at a high mountain observatory

During investigations of the formation of volatile organic compounds (VOCs) in leaves, we observed C5 VOCs during leaf drying, senescence, and following freeze–thaw damage. VOCs were quantified by proton-transfer-reaction mass spectrometry (PTR-MS). In freeze-damaged leaves, VOC products were verified with a gas chromatography PTR-MS system, showing that a variety of plants produced 1-penten-3-ol and 1-penten-3-one with smaller amounts of 2(Z)-penten-1-ol and pentenals; similar VOCs have been detected in soybean seed homogenates (Gardner et al., J. Agric. Food Chem. 44 (1996) 882). Most plants wounded in this way also released hexenals and hexanal, and clover also released methylbutanals. The formation of the C5 products was oxygen–dependent, consistent with the involvement of the enzyme lipoxygenase, and pentenone appeared to form independent of an alcohol dehydrogenase reaction; the latter is apparently disrupted by the freeze–thaw treatment. In parallel with these laboratory experiments, on-line PTR-MS measurements of ambient air were conducted at the Sonnblick Observatory in the Austrian Alps (3106 m a.s.l.). Following a hard freeze in central Austria, substantial amounts of C5 VOCs, ranging from 300 pptv to 6 ppbv and including 1-penten-3-ol, methylbutanals and probably pentenone, were detected at this site for several days peaking after midnight. Factor analysis supported their biogenic origin. We speculate that these VOCs were derived from freeze-damaged local vegetation by processes similar to those seen in laboratory freezing studies. If confirmed, these results suggest that leaf-freezing events in forests will give rise to the release of substantial levels of reactive C5 and C6 VOCs that can contribute to regional tropospheric chemistry.     

Drop size-dependent chemical composition of clouds and fogs. Part II: Relevance to interpreting the aerosol/trace gas/fog system

Size-resolved fog drop chemical composition measurements were obtained during a radiation fog campaign near Davis, California in December 1998/January 1999 (reported in Reilly et al., Atmos. Environ. 35(33) (2001) 5717; Moore et al., Atmos. Environ. this issue). Here we explore how knowledge of this size-dependent drop composition—particularly from the newly developed Colorado State University 5-Stage cloud water collector—helps to explain additional observations in the fog environment. Size-resolved aerosol measurements before and after fog events indicate relative depletion of large (>2 μm in diameter) particles during fog accompanied by a relative increase in smaller aerosol particle concentrations. Fog equivalent air concentrations suggest that entrainment of additional particles and in-fog sedimentation contributed to observed changes in the aerosol size distribution. Calculated deposition velocities indicate that sedimentation was an important atmospheric removal mechanism for some species. For example, nitrite typically has a larger net deposition velocity than water and its mass is found preferentially in the largest drops most likely to sediment rapidly. Gas–liquid equilibria in fog for NO₃⁻/HNO₃, NH₄⁺/NH₃, and NO₂⁻/HONO were examined. While these systems appear to be close to equilibrium or relative equilibrium during many time periods, divergences are observed, particularly for low liquid water content (<0.1 g m⁻³) fogs and in different drop sizes. Knowledge of the drop size-dependent composition provided additional data useful to the interpretation of these deviations. The results suggest that data from multi-stage cloud water collectors are useful to understanding fog processes as many depend upon drop size.     

Variability-lifetime relationship of VOCs observed at the Sonnblick Observatory 1999—estimation of HO-densities

An extensive dataset of VOC measurements was collected at the Sonnblick Observatory, Austria (3106 m) in Fall/Winter 1999/2000, showing high mixing ratios of anthropogenic and biogenic VOCs at this high altitude site due to upward mixing of air masses (Geophys. Res. Lett. 2F (2001) 507). Here we give an interpretation of proton-transfer-reaction (PTR-MS) mass scans obtained in November 1999 based on fragmentation data, GC-PTR-MS analysis and the variability-lifetime relationship, described by the power law, σ(ln(x))=Aτ^−b. The variability-lifetime plot of anthropogenic VOCs gave a proportionality factor A of 1.40 and a,b exponent (sink term) of 0.44 and allowed an estimate of average HO-densities on the order of (1.5±0.4)×10⁵ molecules cm⁻³. Additionally we were able to indirectly determine a diurnal HO-profile with peak values of (1.3±0.5)×10⁶ molecules cm⁻³ around midday. HO-reaction rate coefficients for higher aldehydes (heptanal to nonanal) were estimated due to photochemical losses during a stagnant air episode (27 November) and from the variability-lifetime relationship. Combining long term PTR-MS analysis of VOCs and the variability-lifetime method provides a valuable tool for assessing the dominant cause of the variability in VOC concentrations. This information is essential in understanding the sources and photochemical processing of VOCs detected in ambient air at field measurement sites.     

Temperature and air velocity effects on ethanol emission from corn silage with the characteristics of an exposed silo face

Volatile organic compounds (VOCs) from agricultural sources are believed to be an important contributor to tropospheric ozone in some locations. Recent research suggests that silage is a major source of VOCs emitted from agriculture, but only limited data exist on silage emissions. Ethanol is the most abundant VOC emitted from corn silage; therefore, ethanol was used as a representative compound to characterize the pattern of emission over time and to quantify the effect of air velocity and temperature on emission rate. Ethanol emission was measured from corn silage samples removed intact from a bunker silo. Emission rate was monitored over 12 h for a range in air velocity (0.05, 0.5, and 5 m s^?1) and temperature (5, 20, and 35 °C) using a wind tunnel system. Ethanol flux ranged from 0.47 to 210 g m^?2 h^?1 and 12 h cumulative emission ranged from 8.5 to 260 g m^?2. Ethanol flux was highly dependent on exposure time, declining rapidly over the first hour and then continuing to decline more slowly over the duration of the 12 h trials. The 12 h cumulative emission increased by a factor of three with a 30 °C increase in temperature and by a factor of nine with a 100-fold increase in air velocity. Effects of air velocity, temperature, and air-filled porosity were generally consistent with a conceptual model of VOC emission from silage. Exposure duration, temperature, and air velocity should be taken into consideration when measuring emission rates of VOCs from silage, so emission rate data obtained from studies that utilize low air flow methods are not likely representative of field conditions.     

A study of the atmospheric VOCs of Mount Tai in June 2006

Intensive field investigations were conducted at the summit of Mount Tai in June 2006 to understand the effects of the local and regional sources on atmospheric volatile organic compounds (VOCs) distributions. A total of 60 samples were collected and determined by quantitative analytical methods. The concentrations of the total VOCs (TVOCs) observed in the air of Mount Tai were 6.95 ± 5.71 ppb. Aromatic hydrocarbons provided the largest contribution to TVOCs, followed by alkanes and halocarbons. High levels of halocarbons accounted for 20% of TVOCs due to emission from a PVC plant located at the foot of Mount Tai. Alkenes and cycloalkanes contributed little to the total VOCs. The day-and-night differences and day-to-day variations in the concentrations of four selected species were investigated and the effects of several factors such as meteorological parameters, sources and transport characteristics on them were discussed in details. A back trajectory analysis showed that relatively higher levels of VOCs were related to long-range transport of pollutants from polluted areas. The vertical motions of air masses also had a large impact on the variations of the levels of VOCs. The result of the variability–lifetime relationships of VOCs, which is used to estimate the remoteness of the sampling location, showed that Mount Tai represents intermediate conditions between remote sites and sites in the vicinity of sources.     

Interaction of volatile organic compounds with indoor materials—a small-scale screening method

Indoor air pollution caused by volatile organic compounds (VOCs) may affect the health and well-being of inhabitants. Uptake and release of these compounds by and from indoor materials alter their concentrations in indoor air: uptake will lower peak concentrations, whereas subsequent (slow) release at lower concentration levels will prolong the presence of VOCs in indoor air. An experimental set-up has been implemented where indoor materials are placed as a “membrane” separating two air compartments. Both compartments – consisting of Field and Laboratory Emission Cells FLECs – are constantly flushed with air, one air stream containing a mixture of 20 VOCs, and concentrations in both compartments are measured after 1 h. Ten materials usually covering extensive surfaces indoors were consecutively exposed to the vapour mixture at concentration levels typically found in indoor environments. Under the chosen experimental conditions, five of these materials exhibited a permeability high enough that VOCs could be detected on the other side. Mass transport of VOCs into and through indoor materials has therefore been confirmed by experiment. The set-up allows for a quick screening of indoor materials with respect to their sorption capacity and permeability.     

Determination and potential importance of diterpene (kaur-16-ene) emitted from dominant coniferous trees in Japan

Reactive volatile organic compounds (VOCs) are known to affect atmospheric chemistry. Biogenic VOCs (BVOCs) have a significant impact on regional air quality due to their large emission rates and high reactivities. Diterpenes (most particularly, kaur-16-ene) were detected in all of the 205 enclosure air samples collected over multiple seasons at two different sites from Cryptomeria japonica and Chamaecyparis obtusa trees, the dominant coniferous trees in Japan,. The emission rate of kaur-16-ene, was determined to be from 0.01 to 7.1 μg dwg⁻¹ h⁻¹ (average: 0.61 μg dwg⁻¹ h⁻¹) employing branch enclosure measurements using adsorbent sampling followed by solid phase-liquid extraction techniques. The emission rate was comparable to that of monoterpenes, which is known major BVOC emissions, collected from the same branches. In addition, total emission of kaur-16-ene at 30 °C was estimated to exceed that of total anthropogenic VOC emissions.     

Production and removal of aerosol in a polluted fog layer: model evaluation and fog effect on PM

A radiation fog physics, gas- and aqueous-phase chemistry model is evaluated against measurements in three sites in the San Joaquin Valley of California (SJV) during the winter of 1995. The measurements include for the first time vertically resolved fog chemical composition measurements. Overall the model is successful in reproducing the fog dynamics as well as the temporal and spatial variability of the fog composition (pH, sulfate, nitrate, and ammonium concentrations) in the area. Sulfate production in the fog layer is relatively slow (1–4 μg m⁻³ per fog episode) compared to the episodes in the early 1980s because of the low SO₂ concentrations in the area and the lack of oxidants inside the fog layer. Sulfate production inside the fog layer is limited by the availability of oxidants in the urban areas of the valley and by SO₂ in the more remote areas. Nitrate is produced in the rural areas of the valley by the heterogeneous reaction of N₂O₅ on fog droplets, but this reaction is of secondary importance for the more polluted urban areas. The gas-phase production of HNO₃ during the daytime is sufficient to balance the nitrate removed during the nighttime fog episodes. Entrainment of air from the layer above the fog provides another source of reactants for the fog layer. Wet removal is one of most important processes inside the fog layer in SJV. We estimate based on the three episodes investigated during IMS95 that a typical fog episode removes 500–2000 μg m⁻² of sulfate, 2500–6500 μg m⁻² of nitrate, and 2000–3500 μg m⁻² of ammonium. For the winter SJV valley the net fog effect corresponds to reductions in ground ambient concentrations of 0.05–0.2 μg m⁻³ for sulfate, 3–6 μg m⁻³ for total nitrate, and 1–3 μg m⁻³ for total ammonium.     

Polar and non-polar volatile organic compounds (VOCs) in urban Algiers and saharian sites of Algeria

For the first time, polar and non-polar organic compounds from C₄ to C₂₀ have been identified and quantified in one urban and two saharan sites located in Algeria. They were collected on adsorption traps filled with graphitic carbons and analyzed by high-resolution gas chromatography–mass spectrometry after thermal desorption. More than 190 compounds released by man-made and biogenic sources or formed in air by degradation of photochemical smog precursors were identified in the city center of Algiers. Some of them were never reported before. During our determinations, high levels of pollution characterized the city. Transport of anthropogenic pollutants together with some biogenic emission from date palm trees was mainly responsible for the levels of VOCs measured in Melika oasis located at the entrance of the Sahara desert. Background tropospheric levels of VOCs were instead detected in Bouchene sandy site of the Sahara desert where no biogenic sources were present.     

Constituents of volatile organic compounds of evaporating essential oil

Essential oils containing aromatic compounds can affect air quality when used indoors. Five typical and popular essential oils—rose, lemon, rosemary, tea tree and lavender—were investigated in terms of composition, thermal characteristics, volatile organic compound (VOC) constituents, and emission factors. The activation energy was 6.3–8.6 kcal mol^?1, the reaction order was in the range of 0.6–0.8, and the frequency factor was 0.01–0.24 min^?1. Toluene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, n-undecane, p-diethylbenzene and m-diethylbenzene were the predominant VOCs of evaporating gas of essential oils at 40 °C. In addition, n-undecane, p-diethylbenzene, 1,2,4-trimethylbenzene, m-diethylbenzene, and 1,2,3-trimethylbenzene revealed high emission factors during the thermogravimetric (TG) analysis procedures. The sequence of the emission factors of 52 VOCs (137–173 mg g^?1) was rose ≈ rosemary > tea tree ≈ lemon ≈ lavender. The VOC group fraction of the emission factor of aromatics was 62–78%, paraffins were 21–37% and olefins were less than 1.5% during the TG process. Some unhealthy VOCs such as benzene and toluene were measured at low temperature; they reveal the potential effect on indoor air quality and human health.     

Sensory and chemical characterization of VOC emissions from building products: impact of concentration and air velocity

The emissions from five commonly used building products were studied in small-scale test chambers over a period of 50 days. The odor intensity was assessed by a sensory panel and the concentrations of selected volatile organic compounds (VOCs) of concern for the indoor air quality were measured. The building products were three floor coverings: PVC, floor varnish on beechwood parquet and nylon carpet on a latex foam backing; an acrylic sealant, and a waterborne wall paint on gypsum board. The impacts of the VOC concentration in the air and the air velocity over the building products on the odor intensity and on the emission rate of VOCs were studied. The emission from each building product was studied under two or three different area-specific ventilation rates, i.e. different ratios of ventilation rate of the test chamber and building product area in the test chamber. The air velocity over the building product samples was adjusted to different levels between 0.1 and 0.3 m s^-1. The origin of the emitted VOCs was assessed in order to distinguish between primary and secondary emissions. The results show that it is reasonable after an initial period of up to 14 days to consider the emission rate of VOCs of primary origin from most building products as being independent of the concentration and of the air velocity. However, if the building product surface is sensitive to oxidative degradation, increased air velocity may result in increased secondary emissions. The odor intensity of the emissions from the building products only decayed modestly over time. Consequently, it is recommended to use building products which have a low impact on the perceived air quality from the moment they are applied. The odor indices (i.e. concentration divided by odor threshold) of primary VOCs decayed markedly faster than the corresponding odor intensities. This indicates that the secondary emissions rather than the primary emissions, are likely to affect the perceived air quality in the long run. Some of the building products continued to affect the perceived air quality despite the concentrations of the selected VOCs resulted in odor indices less than 0.1. Therefore, odor indices less than 0.1 as an accept criterion cannot guarantee that a building product has no impact on the perceived air quality.     

Use of thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS) on identification of odorant emission focus by volatile organic compounds characterisation

Volatile organic compounds (VOCs) from several different municipal solid wastes’ treatment plants in Mallorca (Spain) have been analysed by thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS). Ambient (immission) air was collected during February and March 2011 by active sampling onto sorbents Tenax™ TA and Carboxen™ 1000. The study presents the chemical characterisation of 93 volatile organic compounds (VOCs) from an overall set of 84 immission air samples. 70 VOCs were positively identified.The linear fit for all 93 external standard calibration, from 10 mg L⁻¹ to 150 mg L⁻¹ (n = 4), was within the range 0.974 < r² < 0.998. Limits of detection of the method (LOD) for all the standards were within the range 1.1–4,213 pg, as the absolute standard amount spiked into sorbent tubes in 1 μL standard mixture (dissolved in methanol).Overall results stated systematic correlation between waste’s nature and VOCs’ air composition. Organic wastes show main contribution of terpenes, waste water sludge residues’ of reduced sulphured compounds (RSCs) and municipal solid wastes show contribution of a wide sort of VOCs. The use of a chemometric approach for variable’s reduction to 12 principal components enables evaluation of similarities and dissimilarities between facilities. PCA clearly related samples to its corresponding facility on the basis of their VOCs composition and the ambient temperature.     

Spatial and temporal variations in San Joaquin Valley fog chemistry

Fog was sampled at four locations in California’s San Joaquin Valley (SJV) during December 1995 and January 1996 as part of the 1995 Integrated Monitoring Study (IMS95). The fog sampling campaign was conducted in two phases. During the first phase, fog was sampled at three southern SJV surface locations, two urban (Fresno and Bakersfield) and one rural (near the Kern Wildlife Refuge). Both bulk samples (representative of the entire fog drop spectrum) and size-fractionated samples were collected. During the second phase, bulk fog samples were collected at three elevations on a 430 m television transmission tower in the northern SJV, representing some of the first observations of vertical variations in fog composition. SJV fog was observed to be consistently alkaline. The median pH measured in the southern SJV was 6.49, with a range from 4.97 to 7.43. Dominant species in the fog water were ammonium (median southern SJV concentration of 1008 microequivalents/l (μN)), nitrate (483 μN), sulfate (117 μN), acetate (117 μN), formate (63 μN), and formaldehyde (46 μM). Concentrations of the inorganic ions were similar in the urban and rural fogs, although occasionally much higher spikes of S(IV) and sulfate were observed in Bakersfield fog. Acetate, formaldehyde, and total organic carbon, by contrast, were observed to be present in greater concentration in the urban fogs. Bakersfield IMS95 fog concentrations of most species were similar to those measured there in the early 1980s, although concentrations of S(IV) and sulfate were much lower in IMS95 fogs. Significant differences were found between the composition of large and small fog drops, with pH differences at times exceeding one pH unit. The chemical heterogeneity present among SJV fog drop populations is likely to result in significant enhancement of aqueous sulfate production rates over those expected from average fog properties. Significant vertical variations were also observed in fog composition. Liquid water content was observed to increase strongly with elevation, while major ion aqueous concentrations in fog drops decreased with altitude. The total amount of solute contained within the fog (per unit volume of air) was observed to increase with altitude. These observations form a unique data set to be used for model evaluation and for further analysis of aerosol processing by fogs.     

Photochemical oxidant pollution and vegetation: effects of mixtures of gases, fog and particles

Photochemical 'smog' contains mixtures of gases (e.g. ozone, nitrogen dioxide), and dry particles (e.g. nitrates). Intermittent fog in the same geographical area can be acidic with high concentrations of nitric acid. Results from recent field studies in the Los Angeles Basin have emphasized the relative toxicity of these components of photochemical air pollution. Studies have focused on gaseous+fog or gaseous+dry particulate effects on conifers, gaseous+fog effects on crops, and the effects of trace pollutants produced during generation of ozone on crops. Data from these studies indicate that direct alterations in growth and physiological responses were observed only with gaseous pollutants (primarily ozone), or repeated applications of highly acidic fogs (pH < 2.7). Direct particle dry deposition effects are unclear. Few interactions have been found between gaseous pollutants and acidic fog. Charcoal-filtered open-top chambers are highly effective in removing pollutants in the following order: fog (100%) > peroxyacetyl nitrate > ozone > nitrogen dioxide > sulfur dioxide > nitrate ion > ammonium ion > sulfate ion. However, nitric oxide concentrations are higher in charcoal-filtered chambers than in ambient air. The studies point out the importance of considering other components of photochemical pollution in addition to ozone, especially when investigating subtle, long-term effects on vegetation.     

Measurements of Morbidity and Mortality Related to Air Pollution

Examination of total deaths in New York City by day of occurrence shows periodic peaks in mortality which are associated with periods of high air pollution. These peaks are usually associated with periods of low wind speed and temperature inversion conditions which permit air pollution to build up to high levels. Unlike the experience of London, fog is not a necessary part of this picture, and therefore the presence of these episodes is often not apparent at the time to most inhabitants. A characteristic feature of these episodes is the immediate rise in mortality occurring on the same day as the peaks of pollution. A second characteristic is their frequent influence on death rates in the 45–64 year age group as well as in those over 65. These characteristics suggest that if these excess deaths are related to air pollution (as we believe to be highly likely) the mechanism is probably protean and pervasive affecting the course of a variety of different diseases through a basic physiologic effect. The relationship of morbidity in a normal urban population to air pollution is also demonstrated by time series analysis of correlation coefficients. The relation of two symptoms (cough and eye irritation) in a group of 1090 persons observed for three years is compared with two measures of air pollution (SO₂ and particulate density) to which they were exposed. Time lags of up to 28 days were introduced and a constant relationship between air pollution levels and those symptoms was demonstrated.     

Speciation of volatile organic compounds from poultry production

Volatile organic compounds (VOCs) emitted from poultry production are leading source of air quality problems. However, little is known about the speciation and levels of VOCs from poultry production. The objective of this study was the speciation of VOCs from a poultry facility using evacuated canisters and sorbent tubes. Samples were taken during active poultry production cycle and between production cycles. Levels of VOCs were highest in areas with birds and the compounds in those areas had a higher percentage of polar compounds (89%) compared to aliphatic hydrocarbons (2.2%). In areas without birds, levels of VOCs were 1/3 those with birds present and compounds had a higher total percentage of aliphatic hydrocarbons (25%). Of the VOCs quantified in this study, no single sampling method was capable of quantifying more than 55% of compounds and in several sections of the building each sampling method quantified less than 50% of the quantifiable VOCs. Key classes of chemicals quantified using evacuated canisters included both alcohols and ketones, while sorbent tube samples included volatile fatty acids and ketones. The top five compounds made up close to 70% of VOCs and included: 1) acetic acid (830.1 μg m^?3); 2) 2,3-butanedione (680.6 μg m^?3); 3) methanol (195.8 μg m^?3); 4) acetone (104.6 μg m^?3); and 5) ethanol (101.9 μg m^?3). Location variations for top five compounds averaged 49.5% in each section of the building and averaged 87% for the entire building.     

空气中挥发性有机物监测技术的研究进展

讨论了空气中挥发性有机化合物（VOCs）的监测分析方法研究进展。重点介绍了空气中VOCs的采集、分析和测定；简要叙述了样品前处理的新方法--固相微萃取法（SPME）与其它前处理方法的研究概况。     

Inhalation exposure to volatile organic compounds in the printing industry

ABSTRACT

This study reports on the occupational inhalation exposure to VOCs of workers in the Kuwaiti printing industry. Using the evacuated canister methodology, we targeted 72 VOCs in three printeries and compared the concentrations to previous reports and relevant occupational exposure levels (OELs). We found that recent efforts in the printing industry to reduce VOC usage had been successful, as concentrations of key hazardous VOCs were substantially lower than anticipated. On the other hand, nearly all target VOCs were found. Non-production areas were sampled along with the offset printing areas, another strength of this study, and revealed exposures to hazardous VOCs among administers and digital printer and CTP operators. Exposure to ototoxic VOCs amounted to 1–3% of the OEL, consisting mostly of ethylbenzene, which was likely in use in two of the study printeries. Exposure to carcinogenic or probably carcinogenic VOCs was 15–20% of the OEL at four locations across the three printeries, consisting mostly of vinyl chloride and benzyl chloride. Vinyl chloride VOC was partially sourced from outdoors, but was also likely used inside the study printeries. Interestingly, concentrations of vinyl chloride were similar in most sampling locations to that of CFC-114, a CFC banned by the Montreal Protocol and not commonly used as a refrigerant. This unexpected finding suggests further study is warranted to identify the use of these VOCs in printeries. Exposure to hazardous VOCs up to nearly 50% of the OEL, consisting largely of bromoform and vinyl chloride. Bromoform was found in all the study printeries, sourced partially from outdoor air. The higher concentrations found inside the study printeries likely resulted from the use of the desalinated water for washing. This finding raises of emissions from sources other than blanket washes, and inks, etc. adding to the total VOC load in printery indoor air.

Implications: Results from this study indicate that efforts to reduce worker exposure to VOCs particularly dangerous to human health in recent years have been successful, but there is still much to be done to protect workers. Exposures to ototoxic and carcinogenic VOCs were identified, among both production and non-production workers. Unexpected findings included the apparent use in printing activities of the carcinogen vinyl chloride and CFC-114, banned under the Montreal Protocol. Observed lapses in safety procedures included failure to utilize ventilation systems and closing doors between work areas, indicating management and worker education should remain a priority.