PASSIVE SAMPLING DEVICES (PSDs)Silicone Wristbands ANGELA REYES

PSDs -- simple analytic tools that sequester and concentrate bioavailable organic contaminants from the environmentWHY SILICONE?Mimics cell membranesPassive uptake of hydrophobic contaminantsPorousKnown to absorb wide range of compoundsThe Column reported use of explanted silicone prosthesis for bio-monitoring of POPs in humansCheap

Made of PE, POM, and SPME materialsTough, light, flexible plasticPrevious use in aqueous environmentsdetect contamination gradients between sediment and waterHave detected PCBs, PAHs, furans, and chlorinated pesticides (DDT)

DR. KIM ANDERSONProfessor of Environmental & Molecular Toxicology

We use silicone in aqueous environments, why not use it to sample the atmosphere?

2010 lab studies on siliconeModifiable for use as PSD?Initial studies showed promise2014 try in the field

Source: http://fses.oregonstate.edu/Kim-Anderson

PREPARATION & ANALYSIS

Assessed to ensure cleaning process adequate

Post-deployment rinses for extraction

Screened for 1182 chemicals of concern using AMDIS

Gas chromatography-Mass Spectrometery

Pre-clean wristbands using solvents

Vacuum dried

Stored in amber glass jars or PTFE bags

ROBUSTNESS TESTINGPAHs are stable in the wristbandsWristbands can be transported to the lab under ambient conditionsWristbands are chemically secure in PFTE bags

AMBIENT DEMONSTRATIONCan they sequester a wide range of organic compounds?22 participants wore wristbands for 30 days49 DIFFERENT COMPOUNDS IDENTIFIEDPAHsconsumer and personal care productsphthalatesflame retardants compounds used in synthetic material manufacturingHome-use pesticides (DEET & flea meds)2 most detected compounds were diethyl phthalate (all samples) & tonalide cosmetics and fragrances

OCCUPATIONAL STUDY8 roofershot asphalt exposureReduced skin contact improves chemical analyses?3 designssingle, pinned, stackedWork week (8 hour days)5 pre-apprentice roofersTraining Facility8 hr shifthttp://www.cdc.gov/niosh/docs/2003-107/pdfs/2003-107.pdfhttp://www.cdc.gov/niosh/docs/2003-107/pdfs/2003-107.pdf

RESULTSNo discomfort/work interferenceNo statistical difference between configurationsMeasurable levels of PAHsPresent in all samples12 of which on EPA priority listAlso found OPAHs in both settingsBenzofluorenone & fluorenoneNot typically monitored forPotential data gap in occupational exposureTemporal sensitivity

SILICONE WRISTBANDS as PSDsSample atmospheric, time-weighted concentration over exposure periodBased off exposure limits and compliance measurements in situEasy to wear / non-evasiveRelatively inexpensiveValuable tool to address challenges of mixture toxicity

Pesticide risks in West African farmersSilicone PSDLate 2014OSU Dr. Kim Anderson

Ongoing studies needed What shows up

REFERENCESFood Safety and Environmental Stewardship Program. Retrieved February 21, 2015, from http://fses.oregonstate.edu/PSDsStudy Demonstrates Novel Passive Sampling Using Silicone Wristbands. Retreived February 21, 2015 http://www.chromatographyonline.com/node/246733O'Connell, S., Kincl, L., & Anderson, K. (2014). Silicone Wristbands as Personal Passive Samplers. Environmental Science & Technology, 48(6), 3327-35.Anderson, K., Seck, D., Hobbie, K., Traore, A., McCartney, M., Ndaye, A., Forsberg, N., Haigh, T., & Sower, G. (2014). Passive sampling devices enable capacity building and characterization of bioavailable pesticide along the Niger, Senegal and Bani Rivers of Africa. Philosophical Transactions of The Royal Society, 369.

As we know, ppl are exposed to a ton of contaminants in everyday lifeMaking connections btwn contaminant exposure and the onset of disease challengingIn effort to address this, scientists at Oregon State University are currently studying the use of silicone wristbands as a PASSIVE SAMPLING DEVICE in exposure assessment*Passive Sampling Devices are ----

Usually made of:- PE polyethylene- POM poly oxy methylene- SPME solid phase micro-extraction materials

All plastics found in everyday consumer products // pose low risk when used as intended

PCB polychlorinated biphenyls (coolants/lubricants in transformers industrial use)PAHs polycyclic aromatic hydrocarbons (main concern is DNA disruption mutations)

POPs persistent organic pollutants*In 2010, initial studies on silicone were done to see if it can be modified for use as a Passive Sampling Device

Showed promiseSo in 2014, her team decided to try it in the field*Wristbands were pre-cleaned to get rid of background compounds from manufacturing of the wristbandsVacuum driedStored in amber glass jars or Poly tetra fluoro ethylene AIRTIGHT bags- Then sample, pre-cleaned wristbands were assessed to ensure the cleaning process was adequate for quantitative analysisPost-deployment, wristbands were rinsed with purified water & isopropyl alcohol to reduce water residue- Samplers extracted TWICE with 100 mL ethyl acetateThey were then screened for chemicals of concern using AMDIS (an identification software) on a gas chromatography-Mass spectrometer

*Polycyclic Aromatic Hydrocarbons (PAHs) in wristbands & UV StabilityConcentration of PAHs in wristbands exposed to UV light vs shade NO STATISTCAL DIFFERENCEMeaning PAHs are stable in the wristbands in regards to sun exposure

(Next Graph)Here, PAH concentrations were observed under simulated transport at -20 degrees, 23, and +35C for 72 hrs NO STATISTICAL DIFFERENCE between transport conditionsMeaning wristbands can be transported to the lab under ambient conditionsAlso, the wristbands are chemically secure in PFTE bags

*Wore wristbands while working, sleeping, showering, eating--- everything

- Home-use pesticides (DEET & pet flea medication)

*MORE DETAILED LIST FROM THE ACTUAL STUDY

PAHs 9Consumer Products 10 (nicotine, caffeine, and tonalide fragrances / cosmetics / cleaning products)Pesticides 8 (DEET and pet- flea medication)Phthalates 6 (plasticizers)Industrial compounds 14 (mostly flame retardants and plasticizers) *Recruit 8 roofers that would be working with hot asphaltOf which there is known occupational exposure to PAHs

Want to know if reduced skin contact improves chemical analyses

Figure to the left is the recommended protective clothing for roofers, According to the CDC National Institute for Occupational Safety and Health

To the right, we have the different configurations of wristbands employedLapel was pinned on shirt collarThe single wristbandDouble wristband (seen on the top) used to lessen interference from skin contact, if any (sweat)

Roofers wore them for 5 days, 8-hr shifts each day

5 Pre-Apprentice Roofer also participated, working in a training facility for a single 8-hr shift only

*AS A RESULT

- No discomfort nor work interference was reportedNo stat diff was found btwn WRISTBAND configurations in concentrations sequestered- Indicating further studies may be needed to investigate effectiveness of the protective clothing standardsThere were measurable levels of PAHs Which were present in all samples12 of which are on the EPA priority listTo give you an idea, individual PAH concentrations exceeded instrument detection limits from 2 to over 1400 foldConcluded the Wristbands are extremely sensitiveAlso found Oxygenated PAHs that were not typically monitored forPossibly bringing to light a potential data gap in occupational exposure 22 of 23 PAHs and Oxygenated PAHs detected in the 40 hr deployment were also detected in the 8 hr deploymentSuggesting temporal sensitivity= starts absorption of ambient environment right away*In regards to the use of SILICONE WRISTBANDS as Passive Sampling Devices

More research on which pollutants show up and dont show up reliably and regularly need to be done

Theres also research headed by Dr Anderson involving the use of silicone PSDs in assessing pesticide exposures among West African farmers (although not in the form of a wristband)

But Overall, this study has concluded atmospheric, time-weighted average concentrations can be compared with exposure limits and compliance measurements through in situ calibration

Theyre easy to wear , non-evasive,

CHEAP, and

Hopefully, this innovative application of silicone may become a valuable tool in addressing challenges of exposure assessment and mixture toxicity.

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