The prevention of occupational injuries in two industrial plants using an incident reporting scheme

INTRODUCTION: The aim of this study was to examine whether the introduction of an incident reporting scheme with feedback in two industrial plants had an effect on the number of major incidents. METHOD: An intervention design with measurements before the implementation of the incident reporting scheme and two years later was used to examine the relationship between incident rates, safety climate, the willingness to report incidents and perceived management commitment to safety. RESULTS: The results showed that a successful implementation of an incident reporting scheme was followed by a decline in the incidence of major incidents at a Danish metal plant. A key factor in implementing the scheme was top management commitment, which was lacking at another plant, where the implementation of a similar scheme failed. CONCLUSION: Although the study shows some encouraging results concerning the use of incident reporting schemes to prevent occupational accidents, the possibility to draw causal conclusions is limited in the present study, and further studies are needed before the effectiveness of such schemes can be evaluated with certainty.     

Urban meteorological modelling for nuclear emergency preparedness

The main objectives of the current EU project “Integrated Systems for Forecasting Urban Meteorology, Air Pollution and Population Exposure” (FUMAPEX) are the improvement of meteorological forecasts for urban areas, the connection of numerical weather prediction (NWP) models to urban air pollution and population dose models, the building of improved urban air quality information and forecasting systems, and their application in cities in various European climates. In addition to the forecast of the worst air-pollution episodes in large cities, the potential use of improved weather forecasts for nuclear emergency management in urban areas, in case of hazardous releases from nuclear accidents or terror acts, is considered. Such use of NWP data is tested for the Copenhagen metropolitan area and the Øresund region.The Danish Meteorological Institute (DMI) is running an experimental version of the HIRLAM NWP model over Zealand including the Copenhagen metropolitan area with a horizontal resolution of 1.4 km, thus approaching the city-scale. This involves 1-km resolution physiographic data with implications for the urban surface parameters, e.g. surface fluxes, roughness length and albedo. For the city of Copenhagen, the enhanced high-resolution NWP forecasting will be provided to demonstrate the improved dispersion forecasting capabilities of the Danish nuclear emergency preparedness decision–support system, the Accident Reporting and Guidance Operational System (ARGOS), used by the Danish Emergency Management Agency (DEMA).Recently, ARGOS has been extended with a capability of real-time calculation of regional-scale atmospheric dispersion of radioactive material from accidental releases. This is effectuated through on-line interfacing with the Danish Emergency Response Model of the Atmosphere (DERMA), which is run at DMI. For local-scale modelling of atmospheric dispersion, ARGOS utilises the Local-Scale Model Chain (LSMC), which makes use of high-resolution DMI-HIRLAM NWP model data provided to DEMA by DMI four times a day under operational surveillance and covering Denmark and surroundings. The integration of DERMA in ARGOS is effectuated through automated on-line digital communication and exchange of data. The calculations are carried out in parallel for each NWP model to which DMI has access, thereby providing a mini-ensemble of dispersion forecasts for the emergency management.     

Relationship between bioconcentration in fish and steric factors of hydrophobic chemicals

Most polychlorinated naphthalones (PCN) accumulate rapidly according to their hydrophobicity. The uptake and ellmination rate constants are comparable to those of chlorinated benzenes and biphenyls.For most PCN-congeners the resulting bioaccumulation factors show an increase with increasing hydrophobicity. For higher K_d,oct-values (>10⁵) however, no further increase of K_c is observed (K_c. max. = 3.5.10⁴).For the two hepta- and the octachloronaphthalenes no detectable concentrations are found in the fishes, although no restricted blo-availability could be expected. Based on these observations and on data obtained from the literature. a loss of membrane permeation is suggested for hydrophobic molecules with widths over 9.5 Å.In addition a membrane permeation model, as part of the accumulation process of hydrophobic chemicals. Is proposed, which is based on diffusion and partition processes.     

Identification of a potential source of chloroform in urban air: Preliminary Communication

A new potential source of elevated chloroform (CHCl₃) concentrations in urban air is reported. The exhaust gases from gasoline internal combustion engines operated on conventional “leaded” fuel and not equipped with catalytic converters contain parts-per-billion concentrations of chloroform which can, in congested urban areas, contribute significantly to the ambient concentration of chloroform. Exhaust gases from engines burning conventional “leaded” gasoline contain much higher levels of chloroform than do exhaust gases from engines equipped with catalytic converters and operating on “nonleaded” gasoline.     

Joint versus separate estimation of state and change in category frequencies from repeat stratified two-phase sampling with a fallible classifier

Joint maximum likelihood estimates (JML) of category frequencies and change from repeat stratified two-phase samplingsurveys with a fallible classifier are often seriously biased andhave large root mean square errors when they are obtained for small populations (<5000) with three or more categories and amoderate to small phase II sample size (<1000). JML estimates of state also depend on antecedent or posterior data, a recipe for inconsistency. In these situations, a separate maximum likelihood estimation (SML) of category frequenciesat each survey date appears preferable. SML estimates of net change are obtained as the difference in states. SML standard errors of change are obtained via an estimate of the temporal correlation and variances of state. A bivariate binarylogistic model of change provided the estimate of temporal correlation. SML generally outperformed JMLsignificantly in terms of bias and root mean square errors in eight case studies.     

Atmospheric nitrous oxide: patterns of global change during recent decades and centuries

Data from weekly global measurements of nitrous oxide from 1981 to the end of 1996 are presented. The results show that there is more N2O in the northern hemisphere by about 0.7 +/- 0.04 ppbv, and the Arctic to Antarctic difference is about 1.2 +/- 0.1 ppbv. Concentrations at locations influenced by continental air are higher than at marine sites, showing the existence of large land-based emissions. For the period studied, N2O increased at an average rate of about 0.6 ppbv/year (approximately 0.2%/year) although there were periods when the rates were substantially different. Using ice core data, a record of N2O can be put together that goes back about 1000 years. It shows pre-industrial levels of about 287 +/- 1 ppbv and that concentrations have now risen by about 27 ppbv or 9.4% over the last century. The ice core data show that N2O started increasing only during the 20th century. The data presented here represent a comprehensive view of the present global distribution of N20 and its historical and recent trends.     

Determination of maternal serum acetylcholinesterase in pregnancies with fetal neural tube defects

We have investigated the occurrence of acetylcholinesterase (AChE) (E.C.3.1.1.7) in fetal serum, amniotic fluid and maternal serum using an immuno-chemical assay-technique employing both polyclonal and monoclonal antibodies. Fetal serum had increased amounts of AChE, which is due to an increase in the 10.5S form of the enzyme. This form was also found in amniotic fluids of pregnancies with a fetal neural tube defect (NTD), but not in normal amniotic fluid. The increase in amniotic fluid AChE was however, not reflected in the maternal serum.     

Reduction of dioxins and furanes by spray dryer absorption from incinerator flue gas

Reduction of gas phase polychlorinated dibenzodioxins and dibenzofuranes by spray dryer absorption from incinerator flue gas has been investigated. Results from pilot plant and industrial scale spray absorption systems are reported. The results show that conditions for very high removal efficiencies exist for all isomer groups. Total removal above 95% has been achieved.     

Measuring visual opacity using digital imaging technology

The U.S. Environmental Protection Agency (EPA) Reference Method 9 (Method 9) is the preferred enforcement approach for verifying facility compliance with federal visible opacity standards. Supporters of Method 9 have cited its flexibility and low cost as important technological and economic advantages of the methodology. The Digital Opacity Compliance System (DOCS), an innovative technology that employs digital imaging technology for quantifying visible opacity, has been proposed as a technically defensible and economically competitive alternative to Method 9. Results from the field application of the DOCS at EPA-approved Method 9 smoke schools located in Ogden, UT, Augusta, GA, and Columbus, OH, demonstrated that, under clear sky conditions, the DOCS consistently met the opacity error rate established under Method 9. Application of hypothesis testing on the smoke school data set confirmed that the DOCS was equivalent to Method 9 under clear sky conditions. Under overcast sky conditions, human observers seemed to be more accurate than the DOCS in measuring opacity. However, within the smoke school environment, human observers routinely employ backgrounds other than sky (e.g., trees, telephone poles, billboards) to quantify opacity on overcast days. Under conditions that compel the use of sky as plume background (e.g., emission stacks having heights above the tree line), the DOCS appears to be a more accurate methodology for quantifying opacity than are human observers.