Biomarker-based microplastic exposure quantification
A method for quantifying microplastic exposure in a subject includes receiving a blood sample and measuring, using liquid chromatography-mass spectrometry, concentrations of a plurality of non-endogenous chemical biomarkers in the blood sample, wherein each biomarker is associated with at least one microplastic polymer type. The method may include comparing the measured concentrations against baseline contamination levels derived from control samples. Biomarker concentrations attributable to in-vivo microplastic exposure may be identified based at least in part on the comparing. An exposure assessment for the subject may be generated based at least in part on the biomarker concentrations, wherein the exposure assessment indicates exposure levels for one or more microplastic polymer types. The exposure levels may be categorized relative to a population reference dataset and may be mapped to likely sources of microplastic exposure.
1 . A method for quantifying microplastic exposure in a subject, comprising:
receiving a blood sample from the subject;
measuring, using liquid chromatography-mass spectrometry, concentrations of a plurality of non-endogenous chemical biomarkers in the blood sample, wherein each biomarker of the plurality of non-endogenous chemical biomarkers is associated with at least one microplastic polymer type, and wherein the one or more microplastic polymer types comprise at least one of polyethylene terephthalate, polystyrene, or polymethyl methacrylate, and further wherein the plurality of non-endogenous chemical biomarkers comprises at least dimethyl terephthalate, benzoic acid, and terephthalic acid (TPA) as chemical fingerprints indicative of polyethylene terephthalate exposure, at least methacrylic acid and methyl methacrylate as chemical fingerprints indicative of polymethyl methacrylate exposure, and at least styrene as a chemical fingerprint indicative of polystyrene exposure;
comparing the measured concentrations against baseline contamination levels derived from control samples processed through liquid chromatography-mass spectrometry;
identifying, based at least in part on the comparing, biomarker concentrations attributable to in-vivo microplastic exposure; and
generating an exposure assessment for the subject based at least in part on the biomarker concentrations, wherein the exposure assessment indicates exposure levels for one or more microplastic polymer types.
2 . The method of claim 1 , wherein the liquid chromatography-mass spectrometry comprises triple-quadrupole mass spectrometry with multiple reaction monitoring transitions optimized for each biomarker of the plurality of non-endogenous chemical biomarkers.
3 . The method of claim 2 , wherein the multiple reaction monitoring transitions comprise precursor ion to fragment ion transitions defined for each biomarker and configured for selective detection of each biomarker.
4 . The method of claim 1 , further comprising categorizing the exposure levels as low, medium, or high relative to a population reference dataset.
5 . The method of claim 4 , wherein the population reference dataset comprises biomarker concentration distributions derived from at least 500 profiled individuals.
6 . The method of claim 1 , further comprising generating a report that maps the exposure levels to likely sources of microplastic exposure.
7 . The method of claim 6 , wherein the report comprises measured concentrations of each biomarker, polymer-level exposure scores, and normalized exposure categories relative to a population.
8 . The method of claim 1 , wherein receiving the blood sample comprises receiving a blood sample collected using an at-home blood collection device.
9 . The method of claim 8 , wherein the at-home blood collection device comprises a collection vial pre-loaded with lithium heparin anticoagulant.
10 . The method of claim 1 , further comprising validating the blood sample by verifying sufficient blood volume and container integrity prior to measuring the concentrations.
11 . The method of claim 1 , wherein the exposure assessment indicates exposure levels for each of polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polymethyl methacrylate based on a single blood sample.
12 . The method of claim 1 , wherein measuring the concentrations comprises applying calibration curves for each biomarker of the plurality of non-endogenous chemical biomarkers, wherein each calibration curve defines a range of linearity with low, mid, and high calibration points.
13 . The method of claim 1 , further comprising performing quality control by analyzing blank standards to assess background interference and replicates to assess precision, wherein the blank standards are control samples processed identically to the blood sample and nominally free of the plurality of non-endogenous chemical biomarkers, wherein analyzing the blank standards characterizes baseline signals attributable to the liquid chromatography-mass spectrometry instrumentation, and wherein the baseline signals are subtracted or statistically accounted for when identifying the biomarker concentrations attributable to in-vivo microplastic exposure.
14 . The method of claim 1 , wherein the measured concentrations are expressed in micrograms per milliliter.
15 . The method of claim 6 , wherein the report further comprises behavioral recommendations for reducing exposure to one or more of the microplastic polymer types based on the exposure levels.
16 . A system for providing microplastic exposure information to a subject, comprising:
an at-home blood collection kit configured for shipment to the subject, the kit comprising a blood collection device and a collection vial pre-loaded with an anticoagulant;
a laboratory analysis system configured to receive a blood sample and to measure concentrations of a plurality of non-endogenous chemical biomarkers in the blood sample, wherein each biomarker of the plurality of non-endogenous chemical biomarkers is associated with at least one microplastic polymer type, and wherein the one or more microplastic polymer types comprise at least one of polyethylene terephthalate, polystyrene, or polymethyl methacrylate, and further wherein the plurality of non-endogenous chemical biomarkers comprises at least dimethyl terephthalate, benzoic acid, and terephthalic acid (TPA) as chemical fingerprints configured to be indicative of polyethylene terephthalate exposure, at least methacrylic acid and methyl methacrylate as chemical fingerprints configured to be indicative of polymethyl methacrylate exposure, and at least styrene as a chemical fingerprint configured to be indicative of polystyrene exposure;
and a report delivery system configured to electronically transmit an exposure report to the subject, wherein the exposure report comprises: exposure levels for one or more microplastic polymer types derived from the measured concentrations of the plurality of non-endogenous chemical biomarkers, and a categorization of each exposure level as low, medium, or high relative to a population reference dataset.
17 . The system of claim 16 , wherein the laboratory analysis system comprises a triple-quadrupole liquid chromatography-mass spectrometry instrument configured to perform multiple reaction monitoring, wherein the multiple reaction monitoring comprises precursor ion to fragment ion transitions defined for each biomarker and configured for selective detection of each biomarker.
18 . A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, is configured to cause the one or more processors to:
receive biomarker concentration data comprising measured concentrations of a plurality of non-endogenous chemical biomarkers from a blood sample, wherein each biomarker of the plurality of non-endogenous chemical biomarkers is associated with at least one microplastic polymer type, and wherein the one or more microplastic polymer types comprise at least one of polyethylene terephthalate, polystyrene, or polymethyl methacrylate, and further wherein the plurality of non-endogenous chemical biomarkers comprises at least dimethyl terephthalate, benzoic acid, and terephthalic acid (TPA) as chemical fingerprints indicative of polyethylene terephthalate exposure, at least methacrylic acid and methyl methacrylate as chemical fingerprints indicative of polymethyl methacrylate exposure, and at least styrene as a chemical fingerprint indicative of polystyrene exposure;
compare the measured concentrations against a population reference dataset to determine exposure levels for one or more microplastic polymer types;
categorize each exposure level as low, medium, or high relative to the population reference dataset;
generate, based at least in part on the measured concentration comparison, an exposure report comprising the exposure levels and a categorization for each of the one or more microplastic polymer types; and
transmit the exposure report to an electronic device associated with a subject from whom the blood sample was collected.