Sunday, June 9, 2024

Life Exposures and Health

In our daily lives, we are exposed to thousands of substances, yet the impact of many of these chemicals on our health remains unclear. This gap in knowledge is what the Southern Environmental Health Study (SEHS) aims to address. By finding connections between life exposures and health, this study seeks to improve the well-being of all communities. Adults between the ages of 40 and 70 who live in southern states are invited to join this critical research effort. Compensation is provided for participation.

The SEHS is enlisting volunteers to wear specialized wristbands for seven days. These wristbands, designed to absorb a variety of chemicals, provide insight into the substances individuals encounter in their environment and those emanating from their bodies. By participating, you will help to map out the spectrum of chemical exposure over a week, offering a unique window into the interactions with our surroundings.

The wristbands used in this study are equipped with advanced materials capable of absorbing a wide range of chemicals, including:

Polycyclic Aromatic Hydrocarbons (PAHs)

Organophosphate Esters (OPEs)

Pesticides

Plasticizers including Phthalates

Flame Retardants (FRs) 

Polychlorinated Biphenyls (PCBs) and Brominated Flame Retardants (BFRs), including PBDEs (Polybrominated diphenyl ethers)

Nicotine and Cotinine

Phenols

VOCs including Carboxylic Acids, Alcohols, Ketones, Sulfur- and Nitrogen-containing compounds

The wristbands operate through a process known as solid-phase microextraction (SPME), where the material absorbs chemicals directly from the environment and from sweat. These absorbed chemicals are then analyzed using Gas Chromatography-Mass Spectrometry (GC-MS), allowing for the identification and quantification of a wide range of compounds. 

Traditional wristbands can accumulate a wide range of volatile organic compounds (VOCs), but not all materials have a high affinity for molecules like trimethylamine (TMA). TMA is more difficult to be captured due to their high polarity and poor extraction efficiency. One approach to capture these molecules is solid-phase microextraction (SPME), which couples with triple quadrupole gas chromatography tandem mass spectrometry. Previous research on SPME of SCFAs demonstrated poor extraction efficiency, necessitating on-fiber derivatization to enhance detection sensitivity. To improve the capture of molecules like TMA, pre-coating the wristband material with reagents that react with TMA to convert it into a less polar and more easily extractable compound could be employed. Common reagents include pentafluorobenzaldehyde (PFB) or o-phthalaldehyde (OPA). Using materials like ion-exchange resins or functionalized polymers with a high affinity for polar compounds or higher surface area for adsorption would also help. Even with traditional materials, optimized solvent extraction or multi-step extraction processes could improve capture efficiency.

For this study you will be asked to wear a wristband. In the past, participants also wore samplers on their ankles, chest, and shoes. Shoe samplers were more sensitive to particle-bound semi volatile compounds (SVOCs), while chest samplers collected more exhaled compounds. Many chemicals displayed seasonal fluctuations. 


The longer the wristband is worn, the more chemicals accumulate on it.  The wristbands absorb chemicals at a rate proportional to the environmental concentration of these chemicals over time, effectively sampling the environment in a first-order kinetic manner.


To join, click this link

Eligibility: Adults ages 40-70 living in Alabama, Arkansas, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, West Virginia.


REFERENCES

Fuentes ZC, Schwartz YL, Robuck AR, Walker DI. Operationalizing the Exposome Using Passive Silicone Samplers. Curr Pollut Rep. 2022;8(1):1-29. doi: 10.1007/s40726-021-00211-6. Epub 2022 Jan 4. PMID: 35004129; PMCID: PMC8724229.

Roodt AP, Naudé Y, Stoltz A, Rohwer E. Human skin volatiles: Passive sampling and GC × GC-ToFMS analysis as a tool to investigate the skin microbiome and interactions with anthropophilic mosquito disease vectors. J Chromatogr B Analyt Technol Biomed Life Sci. 2018 Oct 15;1097-1098:83-93. doi: 10.1016/j.jchromb.2018.09.002. Epub 2018 Sep 3. PMID: 30212730