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Members of the Board

Introducing the team behind OHTA

The Board consists of nine individuals who are actively engaged in building OHTA. Some are business leaders and senior professionals within national occupational hygiene associations, others are senior occupational hygienists, and a number have been involved with OHTA since the beginning. All are committed to improving standards of occupational hygiene around the world. 

You can often meet them in person at national and international hygiene conferences and they all welcome the chance to talk more about OHTA.

Nancy McClellan MPH, CIH, CHMM

Appointed in early 2017 as Global/Group Industrial Hygiene Manager of LafargeHolcim, and previously Occupational Hygiene Manager at AbbVie Biopharmaceutical, Nancy McClellan has invested over 27 years in practising occupational hygiene in a wide variety of high hazard industries throughout the USA. A past director and committee chair for the American Board of Industrial Hygiene (ABIH) Board of Directors, Nancy is also a member of the British and Irish Occupational Hygiene Societies and has recently been elected to the American Industrial Hygiene Association (AIHA) Board of Directors. A member of the OHTA Leadership Group since 2007, Nancy is now joint Chair of the Board of Trustees of OHTA.


Chris Laszcz-Davis MS, CIH, FAIHA, REPA, AIC Fellow 

As President of The Environmental Quality Organization (EQO) LLC and former Corporate Vice-President, EH&S, Operational Integrity and Product Stewardship, Kaiser Aluminum & Chemical Corporation, Chris has over 35 years of executive management, professional, operational, technical and consulting experience in occupational safety & health, environmental affairs, operational integrity, risk management, product stewardship/quality, strategic planning, auditing, and corporate acquisitions/ divestitures in industry and government. Prior to working for industry, Chris worked for the US Department of Energy (DOE) as a regional Manager.

Chris is an American Industrial Hygiene Association (AIHA) Fellow, an American Institute of Chemists (AIC) Fellow, and a recipient of several awards including national AIHA’s Kusnetz and Alice Hamilton awards. As Past President, American Academy of Industrial Hygiene (AIH), Chris was instrumental in having the profession sponsor its first major Conference on Risk Assessment in the early 1990’s. Chris has served on numerous boards including the American Conference of Governmental Industrial Hygienists (ACGIH) and AIHA, as well as being a Trustee for both the American Board of Industrial Hygiene (ABIH) and the American Industrial Hygiene Foundation (AIHF). When with ABIH, she served as ABIH’s delegate to the IOHA National Accreditation Recognition (NAR) Committee. She is a 2017 member of NIOSH’s Board of Scientific Counselors (BSC), and Past-President/ongoing Board member of California Industrial Hygiene Council (CIHC), an EH&S legislative advocacy group. Chris was also recently appointed to California’s Health & Safety Standards Board by Governor Edmund Brown. Chris is a member of the American Industrial Hygiene Association (AIHA), the British Occupational Hygiene Society (BOHS) and the Australian Institute of Occupational Hygienists (AIOH). Chris is joint Chair of the Board of Trustees of OHTA.



Sarah Leeson MSc DipOH MFOH 

Sarah Leeson has over 25 years experience in Occupational Hygiene, the majority of which has been in the Petrochemical Industry working for ExxonMobil. Sarah is currently the Occupational Hygiene Manager for the Europe, Africa and Middle East region and is based in the UK. One of her roles is to support and encourage employees to progress their Occupational Hygiene training and development. An active Member of BOHS and also a member of the Faculty Board, Sarah joined the OHTA Board in August 2016.


Alan Leibowitz CIH, CSP

Alan Leibowitz is President of EHS Systems Solutions, a consultancy solving leadership and management systems challenges. He previously led ITT’s global EHS and Security program. In this role he directed all program elements including industrial hygiene, business continuity, product safety, auditing and environmental remediation. He is an AIHA Fellow and leader in management systems who led the development of ANSI Z10. He served on the Board of Directors of AIHA, NAEM, RAB and the Center for Safety and Health Sustainability (CSHS). He chaired EHS councils for the Electronic Industries Alliance (EIA), Aerospace Industries Association (AIA) and was a Liaison Delegate to the WBCSD.


Lynn O'Donnell CIH, FAIHA

Lynn O'Donnell received degrees in Nursing, Industrial Hygiene and Management from the University of Virginia, University of Michigan and Aquinas College. From 1977–1990, she worked for the Michigan Department of Public Health, Division of Occupational Health in the areas of compliance, consulting, training and education and health standards promulgation. O’Donnell was certified by ABIH in Comprehensive Practice in 1981 and also received the Bloomfield award from ACGIH that year. She is a Fellow Member of AIHA, served as ABIH Director 1983-1989; Academy Councilor 1986-1988; AIHA Director 1989-1992 and Executive Director of the American Board of Industrial Hygiene from January 1991-June 2014. In 2010, O’Donnell received the AIHA Alice Hamilton Award and was the recipient of the first ABIH Lynn C. O’Donnell Lifetime Achievement Award in 2014. 


David O'Malley DipOH CFFOH

David O'Malley has worked as an Occupational Hygienist for 39 years, both in multinational industry and in consultancy. He has held the BOHS Diploma of Professional Competence in Occupational Hygiene since 1985. A former president of BOHS, he is a Fellow of the Faculty of Occupational Hygiene, and acted as Registrar of the Faculty from 2003 until 2011. David has been involved in OHTA since its inception. He chaired the OHTA Qualifications Group, which developed the examinations system, and was a member of the OHTA Leadership Group until April 2015. David has acted as an Approved Training Provider [ATP] for OHTA courses, teaching in Saudi Arabia, Qatar and South Africa. In January 2016 David became the first Chair of the OHTA Advisory Committee, and in that capacity also rejoined the OHTA Board. 


Hans Thore Smedbold CIH

Hans Thore Smedbold is a senior consultant within Occupational Hygiene in Norway. Over the last few years he has worked mainly in the Norwegian Oil and Gas industry. He is Chief Specialist with Proactima AS and was Managing Director of Occupational Hygiene Solutions AS prior to the merger with Proactima. An active figure in the Norwegian Industrial Hygiene Association, Hans Thore brings valuable experience as an IOHA Board member and as a member of the OHTA Qualifications Group. He has been appointed to the OHTA Board as the IOHA representative, an important conduit between OHTA and the IOHA National Associations' representatives on the IOHA Board.  

Noel Tresider COH, CIH 1984-2017

Noel Tresider is a Fellow of the Australian Institute of Occupational Hygienists (AIOH) with over 35 years' experience as a hygienist. He served on the IOHA Board for eight years and was IOHA President 2011 - 2012. He was Chair of the IOHA National Accreditation Recognition (NAR) Committee for six years and has an understanding of certification schemes around the world. He has received the IOHA 2014 Lifetime Achievement Award and the AIHA 2015 Yant Award. A keen advocate of OHlearning, he has been involved with OHTA since its inception and has written the draft Oil & Gas Module (2014) (Advanced).  


Ross Di Corleto COH, PhD

Ross Di Corleto has been involved in occupational health & safety and occupational hygiene for 35 years with experience in the power industry, mining and refining, nationally within Australia and internationally. He has a Bachelor of Applied Science, Post Graduate Diploma in Occupational Hygiene, a Master of Science by research, and a PhD in occupational health and is Adjunct Associate Professor, University of Queensland.

He is a certified hygienist, a Fellow & Past President of the Australian Institute of Occupational Hygienists and recipient of the AIOH Pamela De Silva Award and a Fellow of the Safety Institute of Australia.

He has been involved in the development and presentation of undergraduate and post graduate modules in occupational health and has lectured at a number of Australian Universities. Ross is currently the Principal Adviser (Global) - Health Risk, for the Rio Tinto resources group based in Brisbane.

Lab bench work

Lab bench work

Using solvent to wash a chemical under vacuum filtration on the laboratory bench

The Board

  • Nancy McClellan
  • Chris Laszcz-Davis
  • Sarah Leeson
  • Alan Leibowitz
  • Lynn O'Donnell
  • David O'Malley
  • Hans Thore Smedbold
  • Noel Tresider  
  • Ross Di Corleto