Presenter Bio: Bharat Chandramouli
A senior scientist with 20+ years of experience in the occurrence, fate and transport of persistent organic pollutants and contaminants of emerging concern. He is a published author on several peer-review articles and book chapters on atmospheric chemistry, per- and polyfluorinated substances (PFAS) measurement, emerging contaminants occurrence, semivolatiles fate and transport and more. In addition to bachelor’s and master’s degrees in engineering and environmental science, Bharat completed his Ph. D in environmental science and atmospheric chemistry from the University of North Carolina, Chapel Hill. At SGS, Bharat directs the development of new products and services in North America, provides technical leadership on analytical methods and coordinates between product development, sales, management and clients to ensure that SGS services meets everyone’s needs.
Per- and polyfluoroalkyl substances (PFAS) have become the most significant emerging contaminant over the last decade with major focus on their occurrence, fate, transport, health effects and problem resolution. PFAS present a massive challenge due to their variety (>6000 PFAS), ubiquity, persistence in the environment due to the carbon-fluorine bond, and the prevalence of chronic health effects. Much of the initial attention on PFAS has focused on exposure from drinking water, especially around sites contaminated from use of aqueous film forming foams (AFFF) containing PFAS. Other exposure sources of concern include occupational health exposure, exposure in indoor air, and diet (especially fish). While PFAS in indoor and ambient have been studied for the last 15 years, there are still large gaps to be addressed on inhalation and air in general as a route of exposure. Areas of focus include occupational health exposure at wastewater treatment plants, landfills, factories, remediation sites, and home/office indoor air from waterproofing treatments and other consumer product sources. What to measure? PFAS monitoring in environmental compartments has focused on semi/non-volatile ionic PFAS such as PFOA and PFOS especially in water. However, research indicates that volatile neutral PFAS such as fluorotelomer alcohols are present at hundreds to thousands of times higher abundance than these ionic PFAS in air, necessitating an air-focused approached at PFAS to monitor. How to sample and measure? Most of the liquid chromatography-mass spectrometry (LC-MS/MS) techniques used for PFAS monitoring in water/soil do not work for volatile PFAS, necessitating methods that are focused on PFAS in air.
In this presentation, we will summarize the current state of science on PFAS exposure in air, what targets are being measured, emerging measurement techniques to measure the PFAS and the state of regulatory development/validation of these methods. We will discuss recent studies showing high levels of PFAS in residences around wastewater treatment systems. We will discuss recent advances both in our laboratories and elsewhere on the development and validation of sampling and measurement for the PFAS most likely to be found in indoor air. Techniques that are in validation/use include thermal-desorption tubes, personal samplers and canisters, passive samplers and gas chromatography-mass spectrometry. Sampling techniques all need validation for capture efficiency, breakthrough and potential for PFAS contamination, We will also discuss recent USEPA and other regulatory progress on measurement, especially on stack emissions and incineration by-products.