Safety lessons and reflections following incinerator vent commissioning in a chemical plant; a case study of a complex socio-technical system

In a bulk chemical plant producing resins, a flashback from an incinerator through the vent system into the reactor hall occurred during commissioning of a newly installed vent header system. The original design of the vent header system was seriously flawed not being in line with current practice. Subsequently the vent header was re-designed into a rich/lean vent header system. This paper explores the reasons behind a number of incidents and near misses that occurred during both the commissioning of a vent header system and its recommissioning following system re-design. Furthermore, it reflects on some broader implications for approaches to safety around what can be recognised as complex socio-technical systems.     

Validating a Safety Climate Model in Metal Processing Industries: A Replication Study

This paper attempts to replicate a safety climate model originally tested in Australia to assess its applicability in a different context: namely, across production workers in 22 medium-sized metal processing organizations in Austria. The model postulates that safety knowledge and safety motivation mediate the relation between safety climate on the one hand and safety compliance and participation on the other. Self-report data from 1075 employees were analyzed using structural equation modeling (SEM). The results of the replication study largely confirmed the original safety climate model. However, in addition to indirect effects, direct links between safety climate and actual safety behavior were found.     

Comparative spray drift studies of aerial and ground applications 1983–1985

The amount of off-site pesticide spray drift from aerial and ground applications was determined at 26 sites across Ontario. These were conducted along transects, parallel and at right angles to the flight path during aerial spray applications and at right angles to the direction of ground spray applications. All sites monitored were where commercial spray operations were in progress. The aerial applications involved both fixed wing aircraft and helicopters and the ground applications involved concentrated air-blast machines and high and low pressure boom sprayers. Deposits of spray drift outside the target area were common to all spray equipment monitored. All except low-pressure boom spraying equipment resulted in measurable spray drift to 80 m off-target with appreciable deposits up to 30–40 m. In a forest spray operation, where insecticide release was the highest, measurable residues were found up to 120 m off-target. The amount of chemical deposited off-target varied with the chemical, the climatical conditions and the equipment used. With a low-pressure boom sprayer, serious drift was confined to 9 m off-target and measurable residues to 15 m.     

Relationships among plant available phosphorus, fertilizer sales, and water quality in northwestern Ohio

Soluble reactive phosphorus (SRP) in northwestern Ohio river water has declined over the past 20 yr in response to decreased applications of fertilizer P. Our objective was to evaluate changes in soluble P (Bray-1 P) levels in the soil over time as influenced by fertilizer P management, cultivation practice, soil properties, and landscape factors. Because soil is the intermediary between added P and SRP measured in river water, we examined the relationship between fertilizer P, soluble soil P, and SRP. Using historical soil survey sample sites as a baseline for original soluble P concentrations (Por), we resampled Ap horizons to establish current levels of soluble P (Pcu). The Por baseline extended from 1953-1982 and Pcu from 1996-1998. Thirty percent of the Pcu values and 17% of the Por values were > or = 40 mg kg(-1). Log-transformed means for Pcu were significantly higher than for Por. The principal determining factors for Por were physiography, soil texture, and soil series. Current P is affected by present tillage practice and drainage class. Change in soluble P in the soil is not as responsive to fertilizer P sales as is SRP in river water. This suggests that as fertilizer P sales decline, a declining percentage of P added as fertilizer is annually dissolved and transported into the drainage system. Soluble P in soil is governed by a combination of fertilizer and tillage management, soil properties, and landscape factors interacting over time.     

The normal fetus of an acardiac twin pregnancy: Perinatal management based on echocardiographic and sonographic evaluation

Experience with three prenatally diagnosed pregnancies complicated by an acardiac twin reveals that ultrasonography and echocardiography are helpful in detecting early signs of in-utero congestive heart failure in the normal twin. The use of Doppler blood flow analysis to determine direction of blood flow, post-mortem placental and fetal angiography, and umbilical cord blood gas determination provided proof that retrograde arterial perfusion occurs in the acardiac fetus. In a fourth pregnancy, an experimental approach to occlude the acardiac twin's umbilical cord was attempted, but was unsuccessful.     

The global troposphere: Biogeochemical cycles,chemistry, and remote sensing

The chemical composition of the troposphere is controlled by various biogeochemical cycles that couple the atmosphere with the oceans, the solid Earth and the biosphere, and by atmospheric photochemical/chemical reactions. These cycles and reactions are discussed and a number of key questions concerning tropospheric composition and chemistry for the carbon, nitrogen, oxygen and sulfur species are identified. Next, we review various remote sensing techniques and instruments capable of measuring and monitoring tropospheric species from the ground, aircraft and space to address some of these key questions. We also consider future thrusts in remote sensing of the troposphere.     

Kinetic Analysis: Benzo(a) pyrene in Southeastern Ohio

Kinetic Analysis has been successful for metallic elements in relatively isolated areas. In this study it is applied to a complex organic compound in a geographical area with a large urban component. Ten media compartments are included, with man as the ultimate receptor. Field data were collected for only 6 of the media and were not used in the analysis but were compared to the calculated steady state concentrations. The greatest differences between calculated and observed values were 4.8-fold for soil and 5.4-fold for sediment. The field sampling regime for soils was biased towards areas of industrialization and probably explains the higher observed value. The lower observed value for sediment is likely due to unknown variables necessary for the estimation of the compartment size and/or the associated transfer rate constants. This study indicated that the Kinetic Analysis technique can be applied successfully to the pre-sampling estimation of the distribution of organic pollutants in environmental systems.     

Rear impact responses of different sized adult Hybrid III dummies

Rear impact sled tests were conducted using 5th, 50th, and 95th percentile Hybrid III dummies to evaluate proposed injury criteria. Different head restraint height (750, 800 mm) and backset (0, 50, 100 mm) positions were used to determine axial and shear forces, bending moments, and injury criteria (NIC, N(ij), and N(km)). The time sequence to attain each parameter was also determined. Three events were identified in the response. Event I was coincident with the maximum rearward motion of the torso, Event II occurred at the time of the peak upper neck flexion moment, and Event III occurred at the time of maximum rearward motion of the head. Parameters such as backset, head restraint height, seat-head restraint interaction, and anthropometry affected impact responses. Head rotations increased with increasing backset and increasing head restraint height. However, N(ij) and N(km) did not exhibit such clear trends. The 50th percentile dummy responded with consistent injury criteria values (e.g., the magnitude of the injury criteria increased with backset increase or head restraint height decrease). However, the 5th and 95th percentile dummies did not demonstrate such trends. These findings underscore the need to include subject anthropometry in addition to seat and head restraint characteristics for better assessment of rear impact responses.