Identification, source and fate of flame-retardants in the environment
: past, present and future concerns

  • Mark J La Guardia

Student thesis: Doctoral Thesis


Over the past 20 years as a senior scientist at the Virginia Institute of Marine Science, I have first-authored 10 and coauthored 18 scientific publications with collaborators from academia, government and the private sector. The focus of these studies included: analytical method development, source identification, bioavailability, biomagnification, degradation and environmental and human health exposure to anthropogenic contaminants known as flame-retardants (FRs). Prior to my Master’s dissertation I conducted scientific investigations that resulted in two first-authored publications and six co-authorships; this included a 2001 communication published in the journal Nature that highlighted land application of FR-laden sewage sludge on agricultural fields as a route of environmental release and possible path for human exposure. My dissertation research produced several publications, including a detailed analysis of the congener composition of the widely used FR, polybrominated diphenyl ether (PBDE) technical mixtures, cited over 1,000 times to date (Google Scholar, date accessed 220419). I followed with several publications on analytical advances, establishing the identities of PBDE degradation products and additional novel-FRs in environmental matrices. From these advances I observed in situ debromination of the PBDE decabromodiphenyl ether (BDE-209) and published on how this process increased BDE-209’s toxicity. I then explored FR distributions in remote areas, co-authoring two publications that identified contributions from Antarctic research bases to that pristine environment and first-authored one of the first papers describing FRs in the continent of Africa. These publications supported the case for restricting the FRs, PBDEs and hexabromocyclododecane in U.S. and European commerce and their later listing as Persistent Organic Pollutants (POPs) by the United Nation’s Stockholm Convention, restricting their usage globally.
I next studied the extent of human exposure from FR treated consumer products, focusing on preadolescent females and those of childbearing years. These individuals have a greater risk of attendant adverse health consequences. Here, I first-authored a paper indicating that, despite the removal of PBDEs from commerce ten years earlier, human exposure continued due to older treated products that remained in use. I then investigated FR exposures in the workplace, which included three co-authorships identifying several workplace exposure scenarios that exceeded those of the general population. In addition, I examined indoor air exposure and first-authored a publication on the contribution of airborne FR-laden particulate size to human exposure.
In conclusion, these contributions improved our knowledge on the sources, fate and exposure to flame-retardants.
Date of AwardSept 2018
Original languageEnglish
Awarding Institution
  • University of Portsmouth
SupervisorGraham Mills (Supervisor)

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