Passive sampling devices

1. A method comprising:

receiving a wearable monitoring device previously worn by a user and information indicative of an amount of time the wearable monitoring device was exposed to an environment, wherein when worn by the user, the wearable monitoring device comprises an absorbent material without a housing;

extracting one or more compounds from the wearable monitoring device;

analyzing the extracted compounds, wherein analyzing the extracted compounds comprises determining at least an amount of a reference compound extracted from the wearable monitoring device and an amount of an environmental compound extracted from the wearable monitoring device; and

based on the amount of the reference compound and the amount of the environmental compound and the information indicative of the amount of time, determining information indicative of the user's exposure to the environmental compound in the environment.

2. The method of claim 1 , comprising purifying the wearable monitoring device; wherein the purified wearable monitoring device is provided to the user to be worn in the environment.

3. The method of claim 2 , wherein purifying the wearable monitoring device comprises cleaning the wearable monitoring device with a solvent.

4. The method of claim 2 , wherein purifying the wearable monitoring device comprises heat treating the wearable monitoring device.

5. The method of claim 2 , comprising providing a purified wearable monitoring device to the user in an airtight container.

6. The method of claim 5 , comprising receiving, from the user, the wearable monitoring device in the airtight container.

7. The method of claim 5 , wherein the airtight container comprises a re-sealable bag.

8. The method of claim 1 , comprising infusing a reference compound into the wearable monitoring device, wherein the infused wearable monitoring device is provided to the user to be worn in the environment.

9. The method of claim 1 , comprising providing pre-paid return packaging to the user, and wherein receiving the wearable monitoring device from the user comprises receiving the wearable monitoring device in the pre-paid return packaging.

10. The method of claim 1 , wherein extracting one or more compounds from the wearable monitoring device comprises extracting the compounds using a solvent extraction process.

11. The method of claim 10 , comprising extracting the compounds into a solvent that is compatible with gas chromatography and liquid chromatography.

12. The method of claim 10 , comprising extracting the compounds into ethyl acetate.

13. The method of claim 1 , wherein extracting one or more compounds from the wearable monitoring device comprises thermally desorbing the compounds from the wearable monitoring device.

14. The method of claim 1 , wherein extracting one or more compounds from the wearable monitoring device comprises extracting one or more of polycyclic aromatic hydrocarbon compounds, compounds from consumer products, pesticides, phthalates, industrial compounds, or volatile organic compounds.

15. The method of claim 1 , in which analyzing the extracted compounds comprises determining one or more of an identity of each of the compounds or an amount of each of the compounds present in the wearable monitoring device.

16. The method of claim 1 , in which determining information indicative of the user's exposure to the compounds in the environment comprises determining a time-weighted average of the user's exposure to each of the compounds.

17. The method of claim 1 , comprising archiving one or more of (i) the extracted compounds or (ii) all or a portion of the wearable monitoring device.

18. The method of claim 1 , wherein the wearable monitoring device comprises an article formed of silicone.

19. The method of claim 18 , wherein extracting the one or more compounds from the wearable monitoring device comprises extracting the one or more compounds from the silicone.

20. The method of claim 18 , wherein when the wearable monitoring device is received, the one or more compounds are sequestered in the silicone.

21. The method of claim 18 , wherein the article formed of silicone is a personal accessory.

22. The method of claim 1 , wherein the wearable monitoring device comprises a wristband.

23. A method comprising:

removing a purified wearable monitoring device from an airtight package;

exposing the wearable monitoring device to an environment, the exposing comprising attaching the wearable monitoring device to a user, wherein the wearable monitoring device that is exposed to the environment and attached to the user comprises an absorbent material without a housing;

tracking an amount of time for which the wearable monitoring device is exposed to the environment; and

sealing the wearable monitoring device in an airtight package for transport to an analysis facility for analysis of compounds sequestered by the wearable monitoring device during exposure of the wearable monitoring device to the environment.

24. The method of claim 23 , wherein the wearable monitoring device comprises a wristband.

25. The method of claim 23 , wherein exposing the wearable monitoring device to an environment comprises wearing the wearable monitoring device in the environment.

26. The method of claim 23 , comprising intermittently exposing the wearable monitoring device to the environment; and tracking a total amount of time for which the wearable monitoring device is exposed to the environment.

27. The method of claim 23 , comprising including, in or with the airtight package, an indication of the amount of time for which the wearable monitoring device was exposed to the environment.

28. A method comprising:

receiving a wearable monitoring device previously worn by a user and information indicative of an amount of time the wearable monitoring device was exposed to an environment, wherein when worn by the user, the wearable monitoring device comprises an absorbent material without a housing;

extracting one or more compounds from the absorbent material;

analyzing the extracted compounds; and

based on the analysis of the extracted compounds and the information indicative of the amount of time, determining information indicative of the user's exposure to the one or more compounds in the environment.

29. The method of claim 28 , wherein the absorbent material comprises silicone.

30. The method of claim 28 , wherein when the wearable monitoring device is received, the one or more compounds are sequestered in the absorbent material.

31. The method of claim 28 , wherein the wearable monitoring device comprises a personal accessory formed of the absorbent material.

32. The method of claim 31 , wherein the personal accessory comprises a wristband.

33. A method comprising:

receiving a wearable monitoring device previously worn by a user and information indicative of an amount of time the wearable monitoring device was exposed to an environment, wherein when worn by the user, the wearable monitoring device comprises an absorbent material without a housing;

cleaning an exterior surface of the absorbent material of the wearable monitoring device;

extracting one or more compounds from the cleaned absorbent material of the wearable monitoring device;

analyzing the extracted compounds; and

based on the analysis of the extracted compounds and the information indicative of the amount of time, determining information indicative of the user's exposure to the one or more compounds in the environment.

34. The method of claim 33 , wherein cleaning the exterior surface of the absorbent material comprises rinsing the absorbent material with water or an organic solvent.

35. The method of claim 33 , wherein cleaning the exterior surface of the absorbent material comprises soaking the absorbent material in an acid.

36. The method of claim 33 , wherein cleaning the exterior surface of the absorbent material comprises sonicating the absorbent material.

37. The method of claim 33 , wherein the absorbent material comprises silicone.

38. The method of claim 37 , wherein the wearable monitoring device comprises a personal accessory formed of silicone.

39. The method of claim 33 , wherein when the wearable monitoring device is received, the one or more compounds are sequestered in the absorbent material.