P Ritchie

Publications of P Ritchie

• Development of a Task-Exposure Matrix (TEM) for Pesticide Use (TEMPEST).

  Authors: F D Dick, S E Semple, M van Tongeren, B G Miller, P Ritchie, D Sherriff, J W Cherrie

  The Annals of occupational hygiene. 03/2010; 54(4):443-52.

  Pesticides have been associated with increased risks for a range of conditions including Parkinson's disease, but identifying the agents responsible has proven challenging. Improved pesticidePesticides have been associated with increased risks for a range of conditions including Parkinson's disease, but identifying the agents responsible has proven challenging. Improved pesticide exposure estimates would increase the power of epidemiological studies to detect such an association if one exists. Categories of pesticide use were identified from the tasks reported in a previous community-based case-control study in Scotland. Typical pesticides used in each task in each decade were identified from published scientific and grey literature and from expert interviews, with the number of potential agents collapsed into 10 groups of pesticides. A pesticide usage database was then created, using the task list and the typical pesticide groups employed in those tasks across seven decades spanning the period 1945-2005. Information about the method of application and concentration of pesticides used in these tasks was then incorporated into the database. A list was generated of 81 tasks involving pesticide exposure in Scotland covering seven decades producing a total of 846 task per pesticide per decade combinations. A Task-Exposure Matrix for PESTicides (TEMPEST) was produced by two occupational hygienists who quantified the likely probability and intensity of inhalation and dermal exposures for each pesticide group for a given use during each decade. TEMPEST provides a basis for assessing exposures to specific pesticide groups in Scotland covering the period 1945-2005. The methods used to develop TEMPEST could be used in a retrospective assessment of occupational exposure to pesticides for Scottish epidemiological studies or adapted for use in other countries.

• Development of an advanced exposure assessment tool for REACH

  Authors: E Tielemans, M Vantongeren, N Warren, W Fransman, J Schinkel, P Ritchie, M Tischer, T Schneider, Hans Kromhout, J Cherrie

  01/2008; 180:S75-S76.

• Retrospective collection of exposure data from industry: results from a feasibility study in the United Kingdom.

  Authors: J W Cherrie, C Sewell, P Ritchie, C McIntosh, J Tickner, D Llewellyn

  Applied occupational and environmental hygiene. 03/2001; 16(2):144-8.

  In the United Kingdom the Health and Safety Executive for some years has stored chemical exposure data in their National Exposure Database. However, it has been difficult to persuade industry andIn the United Kingdom the Health and Safety Executive for some years has stored chemical exposure data in their National Exposure Database. However, it has been difficult to persuade industry and other organizations to contribute to this resource. The aim of this project was to devise a cost-effective method of obtaining occupational exposure data on chemicals from U.K. industry and other sources. Five strategies were used to identify data for three different substances: toluene, acrylonitrile, and ethylene oxide. In total, 810 organizations were contacted and over 45 percent responded. However, only 40 had relevant exposure data. Almost equal numbers of acceptable measurements were identified for toluene and acrylonitrile (2,770 and 2,000 respectively) with lesser ethylene oxide data (800). These measurements were drawn from a wide range of industries and are probably representative of measurements made by U.K. industry, although most of the data were from companies employing more than 100 people. During the second phase of the project, more than 3,000 measurements and associated contextual information were collected (499 for toluene, 1,516 for acrylonitrile, and 17 for ethylene oxide, with a further 1,004 measurements for 1 of 27 substances collected simultaneously with one of the above). The costs of identifying and collecting exposure data ranged from ł7 to ł380 per valid measurement, depending on the source of the data. We suggest that, rather than trying to retrospectively collect data, it is likely to be more cost-effective to enlist a number of occupational hygiene consults and industrial organizations to prospectively provide anonymized exposure measurements for inclusion in the Health and Safety Executives National Exposure Database.

• Voluntary reporting by UK industry of occupational exposure data on chemicals - a feasibility study

  Authors: John W Cherrie, C McIntosh, P Ritchie, C Sewell

  01/1999;

• Tools for regulatory assessment of occupational exposure: development and challenges

  Authors: E. Tielemans, N. Warren, N. Schneider, M. Tischer, P Ritchie, H. Goede, H. Kromhout, J. van Hemmen, J W Cherrie

  REACH (Registration, Evaluation and Authorization of CHemicals) requires improved exposure models that can be incorporated into screening tools and refined assessment tools. These are referred to asREACH (Registration, Evaluation and Authorization of CHemicals) requires improved exposure models that can be incorporated into screening tools and refined assessment tools. These are referred to as tier 1 and 2 models, respectively. There are a number of candidate in tier 1 models that could be used with REACH. Tier 2 models, producing robust and realistic exposure assessments, are currently not available. A research programme is proposed in this paper that will result in a new, advanced exposure assessment tool for REACH. In addition, issues related to variability and uncertainty are discussed briefly, and some examples of tier 1 screening tools are presented. The proposed framework for the tier 2 tool is based on a Bayesian approach, and makes full use of mechanistically modelled estimates and any relevant measurements of exposure. The new approach will preclude the necessity to conduct of case-by-case exposure measurements for each chemical and scenario, since the system will allow for the use of analogous exposure data from relatively comparable scenarios. The development of the new approach requires substantial effort in the area of mechanistic modelling, database development and Bayesian statistical techniques. In thisp aper, the data gapsand areasfor future research are identified to help realise and further improve thisty pe of approach within REACH. A structured data collection and storage system is a central element of the research programme and the availability of this type of tool may also facilitate the sharing of exposure data down and up the supply chain. In addition, new data that are stored according to the proposed structure could enable the validation of any exposure model and thus this programme enhances the exposure assessment field as a whole.