Immunosuppressant medication behaviours in solid organ transplant recipients: a cross-sectional study from south-central China during COVID-19 reopening period.

OBJECTIVE: Medication non-adherence to immunosuppressants threatens allograft survival and function maintenance among solid organ transplant (SOT) recipients. This study aimed to investigate the prevalence of immunosuppressant medication non-adherence and associated factors during the COVID-19 reopening period among Chinese SOT recipients. DESIGN: Cross-sectional study. SETTING: South-central China. POPULATION: Adult patients who received SOT with functioning graft. METHODS: Sociodemographic questionnaire and scales to measure physical activity, depression and medication non-adherence were used to collect data. Logistic regression analysis was conducted to identify factors associated with medication non-adherence. Mediation and moderated mediation analyses were performed to examine the potential mechanisms influencing medication behaviour during the pandemic reopening period using SPSS PROCESS macro 4.3 software. RESULTS: A total of 1121 participants were recruited and the prevalence of medication non-adherence was 36.3% in this study. Recipients who were men, had a higher monthly income, lived alone, had received transplantation for a minimum of 3 years, had received COVID-19 vaccination and experienced depressive symptoms exhibited an increased risk of non-adherence. Contrarily, those who engaged in high-intensity physical activity exhibited a decreased risk. Physical activity was negatively associated with medication non-adherence (r=-0.124, p<0.001) with depression fully mediating this relationship (B=-0.014, 95% CI: -0.032 to -0.003). COVID-19 vaccination significantly moderated the relationship between physical activity and depression (B=-0.303, 95% CI: -0.515 to -0.090). CONCLUSION: This study investigated the prevalence of medication non-adherence among SOT recipients during the COVID-19 reopening period in China, its associated factors and a potential mechanism. Depression fully mediated the association between physical activity and medication non-adherence, and COVID-19 vaccination moderated the relationship between physical activity and depression. These findings provide some insights for managing medication behaviour when confronting public health emergencies. However, relationships displayed in the moderated mediation model should be tracked after returning to normal life and other potential relationships should be explored to deeply understand medication non-adherent behaviour.

Inverse Modeling Revealed Reversed Trends in HCFC-141b Emissions for China during 2018-2020.

Having the highest ozone-depleting potential among hydrochlorofluorocarbons (HCFCs), the production and consumption of HCFC-141b (1,1-dichloro-1-fluoroethane, CH3CCl2F) are controlled by the Montreal Protocol. A renewed rise in global HCFC-141b emissions was found during 2017-2020; however, the latest changes in emissions across China are unclear for this period. This study used the FLEXible PARTicle dispersion model and the Bayesian framework to quantify HCFC-141b emissions based on atmospheric measurements from more sites across China than those used in previous studies. Results show that the estimated HCFC-141b emissions during 2018-2020 were on average 19.4 (17.3-21.6) Gg year-1, which was 3.9 (0.9-7.0) Gg year-1 higher than those in 2017 (15.5 [13.4-17.6] Gg year-1), showing a renewed rise. The proportion of global emissions that could not be exactly traced in 2020 was reduced from about 70% reported in previous studies to 46% herein. This study reconciled the global emission rise of 3.0 ± 1.2 Gg year-1 (emissions in 2020 - emissions in 2017): China's HCFC-141b emissions changed by 4.3 ± 4.5 Gg year-1, and the combined emissions from North Korea, South Korea, western Japan, Australia, northwestern Europe, and the United States changed by -2.2 ± 2.6 Gg year-1, while those from other countries/regions changed by 0.9 ± 5.3 Gg year-1.

[Liver injury caused by exposure to silica and 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123):a case report].

This case report presents two males with drug-induced liver injury acquired from working at a glass factory dealing with silica and 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123). Within one month of work, both patients presented with fever, icterus with liver dysfunction, and eosinophilia. Case 1 had experienced recurrence of symptoms twice while working and showed positive results for the drug-induced lymphocyte stimulation test (DLST). Meanwhile, case 2 was diagnosed by liver biopsy and clinical course but was negative for DLST. Hazard of exposure to non-crystalline silica is low, but drug-induced liver injury after exposure to HCFC-123 has been reported. Allergic liver injury is also caused by chemical substances;however, the insight into whether this injury is caused by exposure to silica or HCFC-123 remains unclear. Further studies are required to examine the influence of silica and HCFC-123 on drug-induced liver injury among glass-factory employees.

Biotic and Abiotic Dehalogenation of 1,1,2-Trichloro-1,2,2-trifluoroethane (CFC-113): Implications for Bacterial Detoxification of Chlorinated Ethenes.

Chlorofluorocarbons including 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) often occur in groundwater plumes comingled with chlorinated solvents such as trichloroethene (TCE). We show that CFC-113 inhibits reductive dechlorination by Dehalococcoides mccartyi (Dhc) in a concentration-dependent manner, causing cis-1,2-dichloroethene (cis-DCE) stalls. Following a 17-day exposure of Dhc-containing consortium SDC-9 to 76 µM CFC-113, cis-DCE dechlorination activity did not recover after CFC-113 removal. River sediment microcosms demonstrated that CFC-113 was subject to microbial degradation under anoxic conditions, and chlorotrifluoroethene (CTFE) was observed as a transformation product. No degradation of CFC-113 was observed in killed controls and in incubations with reactive minerals including mackinawite, green rust, magnetite, and manganese dioxide. In vitro experiments with reduced corrinoid (i.e., vitamin B12) mediated reductive dechlorination of CFC-113 to CTFE and trifluoroethene (TFE) followed by reductive defluorination of TFE to cis-1,2-difluoroethene (cis-DFE) as an end product. This biomimetic degradation of CFC-113 to cis-DFE was also demonstrated in vivo using the corrinoid-producing homoacetogen Sporomusa ovata, suggesting the cometabolic microbial reductive dechlorination and reductive defluorination of CFC-113 to cis-DFE is feasible under anoxic in situ conditions. The CFC-113 degradation intermediates CTFE, TFE, and cis-DFE did not inhibit TCE dechlorination by Dhc, indicating that the initial reductive transformation step can overcome cis-DCE stalls.

Acute liver failure caused by occupational exposure to HCFC-123: Two case reports.

RATIONALE: Hydrochlorofluorocarbon 123 (HCFC-123, Freon123; 2,2-dichloro-1,1,1-trifluoroethane) has been widely used in refrigeration and heat-transfer applications as a substitute for chlorofluorocarbons due to its lower ozone-depleting potentials. Occupational exposure to HCFC-123 may cause mild reversible hepatoxicity, but no fatal cases have been reported yet. PATIENT CONCERNS: In this report, we present cases of severe hepatitis with fatal outcome by HCFC-123. Two industrial workers from a manufacturing factory of fire extinguishers which use HCFC-123 were presented with diarrhea, fever, myalgia, and jaundice. Patients had been repeatedly exposed to the liquid form of HCFC-123 for the past three weeks before flare of symptoms. DIAGNOSIS: The blood biochemistry tests showed acute cholestatic hepatitis and liver biopsy findings indicated inflammatory hepatocellular injury. The diagnosis of HCFC-123 induced hepatitis was made. INTERVENTIONS: The treatment for both patients were generally supportive. The second patient went through hemodialysis, ventilatory care, and artificial liver support therapy (molecular adsorbent recirculating system) at intensive care unit. OUTCOMES: One patient recovered uneventfully, whereas the other patient showed rapid deterioration leading to acute liver failure complicated with cerebral edema, subdural hemorrhage, and death on hospital day 10. LESSONS: The HCFC-123-induced hepatitis showed similarities with halothane hepatitis, both of which may share pathophysiologic mechanisms. Exposure to HCFC-123 needs to be listed as a potential cause of acute liver failure, and to be considered in patients with acute hepatitis of uncertain etiology and negative viral serology.

pH-sensitive pullulan-doxorubicin nanoparticles loaded with 1,1,2-trichlorotrifluoroethane as a novel synergist for high intensity focused ultrasound mediated tumor ablation.

Nanoemulsions as synergists of high intensity focused ultrasound (HIFU) have been widely investigated, since they possess huge potential for improving the efficiency to ablate tumor. However, their clinical applications are limited due to the unsatisfactory phase-transition effect of nanoemulsions during the process of generating nanobubbles. Herein, a novel synergist for HIFU therapy was designed by encapsulating 1,1,2-trichlorotrifluoroethane (CFC) into pH-sensitive pullulan-doxorubicin (Pu-DOX/CFC) nanoparticles. These Pu-DOX/CFC nanoemulsions, with moderate vaporization temperature threshold of 47 °C, could provide favorable phase-transition effect, thus facilitating HIFU energy deposition. Meanwhile, Pu-DOX/CFC nanoemulsions could effectively deliver DOX/CFC to the tumor site and carry out combined therapy. The in vitro and in vivo results confirmed that Pu-DOX/CFC nanoemulsions notably enhanced both ablation and therapeutic efficiency comparing with other synergists. In conclusion, Pu-DOX/CFC nanoemulsions might serve as a novel synergist for HIFU therapy, and possess great potential in clinical implication.

The development of environmentally acceptable fluorocarbons.

Chlorofluorocarbons (CFCs) were introduced in the 1930s as the safe replacements for the toxic and flammable refrigerants being used at that time. Subsequently, hydrochlorofluorocarbons (HCFCs) were also developed. In addition to refrigerant applications, they were used as foam blowing agents, as solvents and as propellants for many aerosols. In the 1970s and 1980s, concern developed about their environmental impact, specifically on stratospheric ozone depletion. Industry began to consider acceptable replacements. In 1987, many of the governments of the world came together and drafted the Montreal Protocol, calling upon Industry to initially phase out production of the CFCs and later HCFCs. Within 4 months of the signing of the Montreal Protocol, the 15 global major producers joined together to form the Alternative Fluorocarbons Environmental Acceptability Study (AFEAS), which sponsored research into environmental effects and the Program for Alternative Fluorocarbons toxicity Testing, PAFT), which examined the toxicology of potential replacements for the CFCs and HCFCs. Nine replacements were identified by companies and, through this international cooperation; toxicology programs were designed, conducted, and evaluated without duplication of effort and testing; consequently these new products were introduced within less than 10 years. Indeed the Montreal Protocol has been recognized as the most appropriate international treaty to phase-down HFCs. In 2016 the Kigali Amendment to the Montreal Protocol set out a phase-down schedule for the consumption and production of HFCs. In order to reduce the consumption and emissions of high GWP HFCs. Recently lower GWP HFCs and very low GWP HFOs (hydrofluoroolefins and HCFOs (hydrochlorofluoroolefins) have been introduced into a range of applications. Summaries of the toxicology profiles of some of the original CFCs and HCFCs, the replacements and the new post-PAFT replacements are described. The chemicals in this review include CFC-11, CFC-12, CFC-113, CFC-114, HCFC 22, HCFC-123, HCFC-124, HCFC-141b, HCFC-142b, HCF-32, HFC-125, HFC-134a, HFC-143a, HFC-152a, HFC-245ea, HFC-245fa, HFO-1234yf, HFO-1234ze, and HCFO-1233zd.

Atmospheric Degradation Initiated by OH Radicals of the Potential Foam Expansion Agent, CF3(CF2)2CH═CH2 (HFC-1447fz): Kinetics and Formation of Gaseous Products and Secondary Organic Aerosols.

The assessment of the atmospheric impact of the potential foam expansion agent, CF3(CF2)2CH═CH2 (HFC-1447fz), requires the knowledge of its degradation routes, oxidation products, and radiative properties. In this paper, the gas-phase reactivity of HFC-1447fz with OH radicals is presented as a function of temperature, obtaining kOH (T = 263-358 K) = (7.4 ± 0.4) × 10(-13)exp{(161 ± 16)/T} (cm(3)·molecule(-1)·s(-1)) (uncertainties: ±2σ). The formation of gaseous oxidation products and secondary organic aerosols (SOAs) from the OH + HFC-1447fz reaction was investigated in the presence of NOx at 298 K. CF3(CF2)2CHO was observed at low- and high-NOx conditions. Evidence of SOA formation (ultrafine particles in the range 10-100 nm) is reported with yields ranging from 0.12 to 1.79%. In addition, the absolute UV (190-368 nm) and IR (500-4000 cm(-1)) absorption cross-sections of HFC-1447fz were determined at room temperature. No appreciable absorption in the solar actinic region (λ > 290 nm) was observed, leaving the removal by OH radicals as the main atmospheric loss process for HFC-1447fz. The major contribution of the atmospheric loss of HFC-1447fz is due to OH reaction (84%), followed by ozone (10%) and chlorine atoms (6%). Correction of the instantaneous radiative efficiency (0.36 W m(-2)·ppbv(-1)) with the relatively short lifetime of HFC-1447fz (ca. 8 days) implies that its global warming potential at a time horizon of 100 year is negligible (0.19) compared to that of HCFC-141b (782) and to that of modern foam-expansion blowing agents (148, 882, and 804 for HFC-152a, HFC-245fa and HFC-365mfc, respectively).

An outbreak of refrigerant-induced acute hepatitis in Hong Kong.

We report a cluster of acute hepatitis in five air-conditioning maintenance workers following accidental exposure to 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123). They presented to us with complaints of feverishness, generalised malaise, and epigastric discomfort. Their blood biochemistry tests were compatible with acute hepatitis. Viral hepatitis serology, tests for autoimmune hepatitis, and analyses for drugs and alcohol consumption were all negative. No focal hepatic lesion was detected by ultrasound imaging. Percutaneous liver biopsy samples were taken from two of them. The patients were managed with supportive treatment. All had spontaneous, but slow, recovery. Their liver function tests returned to normal after 4 months and their outcomes were favourable. Physicians should be aware of this occupational disease entity.

Chemical exposure levels in printing workers with cholangiocarcinoma.

OBJECTIVE: This study aimed to identify chemicals used by printing workers with cholangiocarcinoma, as well as the levels of exposure to the chemicals. METHODS: Information necessary to identify chemicals used by printing workers with cholangiocarcinoma and to estimate chemical exposure concentrations was obtained from the Ministry of Health, Labour and Welfare, Japan. Working environment concentrations of the chemicals in the printing rooms were estimated using a well-mixed model, and exposure concentrations during the ink removal operation were estimated using a near-field and far-field model. Shift time- weighted averages (TWA) of exposure concentrations were also calculated. RESULTS: Two workers from each of three small printing plants examined suffered from cholangiocarcinoma, and all six of these workers had been exposed to 1,2-dichloropropane (1,2-DCP) for 10-16 years. The estimated working environment concentrations of 1,2-DCP in the printing rooms were 17-180 ppm and estimated exposure concentrations during the ink removal operation were 150-620 ppm. Shift TWA values were estimated to be 62-240 ppm. Four of the six workers had also been exposed to dichloromethane (DCM) at estimated working environment concentrations of 0-98 ppm and estimated exposure concentrations during the ink removal operation of 0-560 ppm. Shift TWA values were estimated to be 0-180 ppm. Other chlorinated organic solvents (1,1,1-trichloroethane, 1,1-dichloro-1-fluoroethane) and petroleum solvents (gasoline, naphtha, mineral spirit, mineral oil, kerosene) were also used in the ink removal operation. CONCLUSIONS: All six printing workers with cholangiocarcinoma were exposed to very high levels of 1,2-DCP for a long term.

Cell adhesion response on femtosecond laser initiated liquid assisted silicon surface.

Silicon substrates were irradiated at normal incidence with a femtosecond Ti:sapphire laser (Quatronix, 90 fs pulse duration, 1 kHz repetition rate, M(2) ~ 1.2, maximum energy peak 350 mJ ) operating at a wavelength of 400 nm and focused via a microscope objective (Newport; UV Objective Model, 37x 0.11 N.A.). The laser scanning was assisted by liquids precursors media such as methanol and 1,1,2-trichlorotrifluoroethane. By altering the processing parameters, such as incident laser energy, scanning speed, and different irradiation media, various surface structures were produced on areas with 1 mm(2) dimensions. We analyzed the dependence of the surface morphology on laser pulse energy, scanning speed and irradiation media. Well ordered areas are developed without imposing any boundary conditions for the capillary waves that coarsens the ripple pattern. To assess biomaterial-driven cell adhesion response we investigated actin filaments organization and cell morphological changes following growth onto processed silicon substrates. Our study of bone cell progenitor interaction with laser nanoprocessed silicon lines has shown that cells anchor mainly to contact points along the nanostructured surface. Consequently, actin filaments are stretched towards the 15 µm wide parallel lines increasing lateral cell spreading and changing the bipolar shape of mesenchymal stem cells.

Reformulation of Stmerin(®) D CFC formulation using HFA propellants.

Stmerin(®) D was reformulated using hydrofluoroalkanes (HFA-134a and HFA-227) as alternative propellants instead of chlorofluorocarbons (CFCs), where the active ingredients were suspended in mixed CFCs (CFC-11/CFC-12/CFC-114). Here, we report the suspension stability and spray performance of the original CFC formulation and a reformulation using HFAs. We prepared metered dose inhalers (MDI) using HFAs with different surfactants and co-solvents, and investigated the effect on suspension stability by visual testing. We found that the drug suspension stability was poor in both HFAs, but was improved, particularly for HFA-227, by adding a middle chain fatty acid triglycerides (MCT) to the formulation. However, the vapor pressure of HFA-227 is higher than a CFC mixture and this increased the fine particle dose (FPD). Spray performance was adjusted by altering the actuator configuration, and the performance of different actuators was tested by cascade impaction. We found the spray performance could be controlled by the configuration of the actuator. A spray performance comparable to the original formulation was obtained with a 0.8 mm orifice diameter and a 90° cone angle. These results demonstrate that the reformulation of Stmerin(®) D using HFA-227 is feasible, by using MCT as a suspending agent and modifying the actuator configuration.

How to improve reliability in groundwater analysis: over a decade of experience with external quality control in field campaigns on volatile halogenated compounds.

The reliability in measurement results obtained during environmental monitoring is crucial for the assessment and further planning of remediation efforts on the respective contaminated sites by the responsible authorities. A case study concerned with groundwater contaminated with perchloroethylene, trichloroethylene and 1,1,2-trichlorotrifluoroethane including their degradation products which involves private contract laboratories and an independent provider of quality assurance (QA) is presented. The experience gained with biannual monitoring campaigns over 14 years indicates that the selection of contractors on basis of accreditation status and successful performance in interlaboratory comparisons are not sufficient. Rather the auditing of the contractors by the QA provider prior to each campaign and the crosschecking of selected monitoring samples by the QA provider led to a lasting improvement of reliability in the contractors' measurement results. A mean deviation of 20% from the reference value determined by the QA provider for the crosschecked samples was reached.

Simultaneous analysis of atmospheric halocarbons and non-methane hydrocarbons using two-dimensional gas chromatography.

A gas chromatographic system was constructed to simultaneously measure ambient non-methane hydrocarbons (NMHCs) and halocarbons, which play significant roles in tropospheric ozone formation and stratospheric ozone loss, respectively. A heart-cut device based on a Deans switch was connected to two capillary columns to cover the full range of NMHCs and halocarbons. Analytes more volatile than C(6) NMHCs and the halocarbon CFC-113 were separated with a PLOT column, while the remaining less volatile compounds were separated with a DB-1 column. Merge-and-split of the flows at the end of the two columns allowed the NMHCs and halocarbons to be observed simultaneously by electron capture detection (ECD) and flame ionization detection (FID). To avoid peak-overlap from the two columns while merging, programmed pressures were incorporated to control the Deans switch. In addition to the advantage of measuring two important classes of compounds in the atmosphere at the same time, this method has the additional benefit of using the homogeneity of atmospheric CFC-113 as an "intrinsic" internal reference. Thus, better data continuity, less consumption of gas standards, and real-time quality control can all be achieved.

Simultaneous determination of CFC-11, CFC-12 and CFC-113 in seawater samples using a purge and trap gas-chromatographic system.

We have optimized the analytical parameters of a homemade instrument for the simultaneous measurement of the chlorofluorocarbons CCl(2)F(2) (CFC-12), CCl(3)F (CFC-11) and C(2)Cl(3)F(3) (CFC-113) in seawater. Seawater samples are flame sealed into 60 ml glass ampoules avoiding any contact with the atmosphere and stored in cold, dark condition until analysis. In the laboratory, after cracking the ampoule in an enclosed chamber filled with ultra-pure nitrogen, the seawater sample is transferred to a stripping chamber, where ultra-pure nitrogen is used to purge the dissolved CFCs from the seawater. The extracted gases are then cryogenically trapped, subsequently the trap is isolated and heated and the CFCs are transferred by a carrier gas stream into a precolumn and then are separated on a gaschromatographic packed column. To separate adequately CFC-12 from N(2)O, during the early part of the chromatographic run, the gas stream passes through a molecular sieve, which is then isolated and backflushed. The CFCs are detected on an electron capture detector ((63)Ni ECD). After a careful choice of the experimental conditions, the performances of the system were evaluated. The detection limits for seawater samples are: 0.0081 pmol kg(-1) for CFC-12, 0.0073 pmol kg(-1) for CFC-11 and 0.0043 pmol kg(-1) for CFC-113. The reproducibility of replicate samples lies within 5% for the three CFCs. The system has been successfully employed for CFC measurements in seawater samples collected in the Ross Sea (Antarctica) in the framework of the Italian Antarctic research project.

Three-dimensional modeling of HCFC-123 in the atmosphere: assessing its potential environmental impacts and rationale for continued use.

HCFC-123 (C2HCl2F3) is used in large refrigeration systems and as a fire suppression agent blend. Like other hydrochlorofluorocarbons, production and consumption of HCFC-123 is limited under the Montreal Protocol on Substances that Deplete the Ozone Layer. The purpose of this study is to update the understanding of the current and projected impacts of HCFC-123 on stratospheric ozone and on climate and to discuss the potential environmental effects from continued use of this chemical for specific applications. For the first time, the Ozone Depletion Potential (ODP) of a HCFC is determined using a three-dimensional model (MOZART-3) of atmospheric physics and chemistry. All previous studies have relied on results from two-dimensional models. The derived HCFC-123 ODP of 0.0098 is smaller than previous values. Analysis of the projected uses and emissions of HCFC-123, assuming reasonable levels of projected growth and use in centrifugal chiller and fire suppressant applications, suggests an extremely small impact on the environment due to its short atmospheric lifetime, low ODP, low Global Warming Potential (GWP), and the small production and emission of its limited applications. The current contribution of HCFC-123 to stratospheric reactive chlorine is too small to be measurable.

Halocarbon emissions from the United States and Mexico and their global warming potential.

We use recent aircraft measurements of a comprehensive suite of anthropogenic halocarbons, carbon monoxide (CO), and related tracers to place new constraints on North American halocarbon emissions and quantify their global warming potential. Using a chemical transport model (GEOS-Chem) we find that the ensemble of observations are consistent with our prior best estimate of the U.S. anthropogenic CO source, but suggest a 30% underestimate of Mexican emissions. We develop an optimized CO emission inventory on this basis and quantify halocarbon emissions from their measured enhancements relative to CO. Emissions continue for many compounds restricted under the Montreal Protocol, and we show that halocarbons make up an important fraction of the total greenhouse gas source for both countries: our best estimate is 9% (uncertainty range 6-12%) and 32% (21-52%) of equivalent CO2 emissions for the U.S. and Mexico, respectively, on a 20 year time scale. Performance of bottom-up emission inventories is variable, with underestimates for some compounds and overestimates for others. Ongoing methylchloroform emissions are significant in the U.S. (2.8 Gg/y in 2004-2006), in contrast to bottom-up estimates (< 0.05 Gg), with implications for tropospheric OH calculations. Mexican methylchloroform emissions are minor.

Uncontrolled occupational exposure to 1,1-dichloro-1-Fluoroethane (HCFC-141b) is associated with acute pulmonary toxicity.

BACKGROUND: The toxicity of 1,1-dichloro-1-fluoroethane (HCFC-141b), a hydrochlorofluorocarbon (HCFC), is low according to animal studies. However, pulmonary manifestations associated with acute HCFC exposure by inhalation have not been reported as yet in man. We evaluated the pulmonary effects of HCFC-141b inhalation, caused by an accident, in previously healthy individuals. METHODS: The subjects in this study were 15 workers in whom unpleasant symptoms developed after inhaling HCFC-141b at work. Clinical manifestations, radiologic findings, and changes in pulmonary function and airway hyperresponsiveness (AHR) over time were assessed, and BAL fluid analyses findings for four subjects were compared with those of four healthy volunteers (control subjects). RESULTS: (1) Cough, shortness of breath, and malaise developed in most patients, but only two patients complained of a sore throat. (2) A high-resolution CT scan of the chest revealed bilateral diffuse ground-glass opacities that were predominant in upper lung zones. (3) The mean (+/- SD) FVC was 71.4 +/- 18.86% predicted, and the mean FEV(1)/FVC ratio was 92.9 +/- 4.25%. Eleven patients (73%) showed restrictive ventilatory impairments during the initial tests. FVC gradually improved, and the FEV(1)/FVC ratio gradually decreased with time. (4) AHR was observed in four subjects during the initial tests. (5) BAL fluid samples revealed significantly higher neutrophil counts than those in control subjects. CONCLUSIONS: Overexposure to HCFC-141b was associated with parenchymal lung injury that was characterized by ground-glass opacities, elevated BAL neutrophil counts, and restrictive ventilatory impairment. Restrictive impairments improved with time after exposure.

European emissions of HFC-365mfc, a chlorine-free substitute for the foam blowing agents HCFC-141b and CFC-11.

HFC-365mfc (1,1,1,3,3-pentafluorobutane) is an industrial chemical used for polyurethane foam blowing. From early 2003, HFC-365mfc has been commercially produced as a substitute for HCFC-141b, whose use in Europe has been banned since January 2004. We describe the first detection of HFC-365mfc in the atmosphere and report on a 2 year long record at the high Alpine station of Jungfraujoch (Switzerland) and the Atlantic coast station of Mace Head (Ireland). The measurements at Jungfraujoch are used to estimate the central European emissions of HFC-365mfc, HCFC-141b, and CFC-11. For HFC-365mfc, we estimate the central European emissions (Germany, France, Italy, Switzerland, The Netherlands, Belgium, and Luxembourg) in 2003 and 2004 as 400-500 tonnes year(-1). These emissions are about one-third lower on a per capita basis than what we estimate from the Mace Head measurements for the total of Europe. The estimated emissions of HCFC-141b for central Europe are higher (i.e., 7.2-3.5 ktonnes year(-1)) with a decreasing trend in the period from 2000 to 2004. Residual emissions of CFC-11 are estimated at 2.4-4.7 ktonnes year(-1) in the same time period. The Po Valley (northern Italy) appears to be a main source region for HFC-365mfc and for the former blowing agents HCFC-141b and CFC-11. In 2004, the emissions of HFC-365mfc arose from a wider region of Europe, which we attribute to an increased penetration of HFC-365mfc into the European market.

Airborne methylene diphenyl diisocyanate (MDI) concentrations associated with the application of polyurethane spray foam in residential construction.

The primary objectives of this study were (a) to measure potential exposures of applicators and assistants to airborne methylene diphenyl diisocyanate (MDI), (b) to measure airborne concentrations of MDI at various distances from the spray foam application, and (c) to measure airborne MDI concentrations as a function of time elapsed since application. Other study objectives were, (a) to compare the results from filter and impinger samples; (b) to determine the particle size distribution in the spray foam aerosol; (c) to determine potential exposures to dichlorofluoroethane; and (d) to measure any off-gassing of MDI after the foam had fully cured. This study was conducted during application of spray polyurethane foam inside five single-family homes under construction in the United States and Canada. Spray foam applicators and assistants may be exposed to airborne MDI concentrations above the OSHA permissible exposure limit. At these concentrations, OSHA recommends appropriate respiratory protection during spray foam application to prevent airborne MDI exposures above established limits and to protect against exposure to dichlorofluoroethane (HCFC-141b). Airborne MDI concentrations decrease rapidly after foam application ceases. The highest airborne concentrations measured after 15 min and 45 min were 0.019 mg/m3 and 0.003 mg/m3, respectively. After 45 min, airborne concentrations were below the limit of quantitation (LOQ) of 0.036-microg per sample. For samples taken 24 hours after completion of foaming, results were also below the LOQ. Approximately two-thirds of the total mass of the airborne particles in the spray foam aerosol was greater than 3.5 microns in diameter. Airborne MDI concentrations determined by filter sampling methods were 6% to 40% lower than those determined by impinger methods.