John Tickner

Publications of John Tickner

• Trends in inhalation exposure--a review of the data in the published scientific literature.

  Authors: Karen S Creely, Hilary Cowie, Martie van Tongeren, Hans Kromhout, John Tickner, John W Cherrie

  The Annals of occupational hygiene. 12/2007; 51(8):665-78.

  As part of a larger study aimed at identifying the long-term changes in inhalation exposure for selected hazardous substances in a number of industrial sectors within the UK, we have reviewed theAs part of a larger study aimed at identifying the long-term changes in inhalation exposure for selected hazardous substances in a number of industrial sectors within the UK, we have reviewed the published literature on temporal changes in inhalation exposure. Scientific papers and reports of interest were identified using standard literature review techniques. Most studies did not express the results as relative annual trends in exposure, and so where possible the data were reanalysed using regression methods to produce estimates of the average annual percentage change in concentration. In the majority of instances, there were significant reductions in exposure, with percentage yearly declines up to 32%. In many studies, information about changes in the working environment, process conditions or other factors that may have influenced the change in exposure over time was lacking. Factors commonly cited as being responsible for exposure reductions included the introduction of new standards and response to regulatory requirements as well as changes in production methods. A large number of exposure measurement datasets exist for many industrial sectors for most of the second half of the 20th century and this resource has allowed us to identify trends in occupational exposure. It is most important that longitudinal exposure data continue to be collected along with relevant contextual information to enable future changes to be adequately assessed.

• Trends in inhalation exposure mid 1980s till present

  Authors: KS Creely, Martie van Tongeren, D While, AJ Soutar, John Tickner, M Agostini, F De Vocht, Hans Kromhout, M Graham, A Bolton, Hilary Cowie, John W Cherrie

  01/2006;

  RR460 - Trends in inhalation exposure mid 1980s till present

• The development of the EASE model.

  Authors: John Tickner, Jeff Friar, Karen S Creely, John W Cherrie, D Eric Pryde, John Kingston

  The Annals of occupational hygiene. 04/2005; 49(2):103-10.

  The estimation and assessment of substance exposure (EASE) model has been under development and in use since the early 1990s. It is a general model that can be used to predict workplace exposure toThe estimation and assessment of substance exposure (EASE) model has been under development and in use since the early 1990s. It is a general model that can be used to predict workplace exposure to any substance hazardous to health. The current EASE model (version 2.0) has been used widely in the risk assessment of new and existing chemicals by the UK Health and Safety Executive (HSE) and other regulatory agencies. EASE has also been distributed globally to over 200 users and therefore may have been used for many other purposes. Despite widespread use of the model, neither the development of its structure nor its underlying concepts and principles have been published in the open literature. Using surviving documentary evidence and discussions with key personnel, the creation and development of the model from 1992 to 2002 is described. The role of the HSE's National Exposure Database (NEDB) as the principal data source for the development of the model output exposure ranges is described. A number of problems and limitations of the model have been identified and the description of the model's development provides some explanation of their presence.

• Evaluation and further development of EASE model 2.0

  Authors: Karen S Creely, John Tickner, Graeme W Hughson, D Eric Pryde, Nicholas D Warren, R Rae, C D Money, Andrew Phillips, John W Cherrie

  01/2005; 49:135-45.

  EASE (Estimation and Assessment of Substance Exposure) is a general model that may be used to predict workplace exposure to a wide range of substances hazardous to health. First developed in theEASE (Estimation and Assessment of Substance Exposure) is a general model that may be used to predict workplace exposure to a wide range of substances hazardous to health. First developed in the early 1990s, it is now in its second Windows version. This paper provides a critical assessment of the utility and performance of the EASE model, and on the basis of this review, recommendations for the structure of a revised model are outlined. Twenty-seven stakeholders were interviewed about their previous use of EASE, perceived advantages and limitations of the model and suggestions for improvement. A subset of stakeholders was contacted on a second occasion to determine their views on the preferred outputs for an ideal exposure assessment model. Overall, stakeholders felt that the model should be updated to provide more accurate and precise exposure assessments. However, users also expressed the view that the simplicity and usability of the software model should not be compromised. Six studies investigating the validity of the inhalation exposure assessment section of EASE were identified. These showed that the model generally either predicted close to the measured exposures or overestimated exposure; though performance was highly variable. Two studies investigated the validity of the dermal exposure assessment and found that EASE produced considerable overestimates of actual dermal exposure (the amount of a substance that actually lands on the skin). A conceptual model of exposure was developed to investigate whether the structure of the EASE model is appropriate. Although EASE has a number of characteristics that describe exposure, it is a greatly simplified model and does not include all the important exposure determinants. More importantly, EASE can produce estimates of exposure that are ambiguous or incomplete. Our conceptual model may provide a rational basis for developing an improved version of EASE but further consultation is needed to decide the purpose and intended use of any successor to EASE.