The Exposome Collaborative at Johns Hopkins University is involved in the following projects:
Project 1. Characterizing the External and Internal Components of the Exposome in Relation to Childhood Asthma in Baltimore City.
Asthma prevalence in the US is 9.4% and there are strong known environmental contributions to disease development and severity. While genetic factors are thought to contribute 40–60% to the overall asthma risk [Caroll et al], this suggests the other half is due to environmental contributions. For this study The Exposome Collaborative at Johns Hopkins will provide a comprehensive exposome assessment for participants of an ongoing Childhood Asthma study.
The Exposome Collaborative @ JHU Measures the Exposome
Exposure sources for these participants include air pollution mixtures from vehicular traffic, crude oil trains, point sources such as the solid waste incineration, soil pollution from past industrial activities, plus indoor sources including tobacco smoke, cooking emissions, and cleaning products, and emerging contaminants in drinking water. The participants have been selected such that an exposure gradient can be detected as well as clustering due to the various sources in the different neighborhoods, even though they may otherwise have similar socio-demographics. Measurements include exposure assessment during residential visits and biomarkers in tissue samples. From each participant, the following samples have been collected.
- Personal and/or residential measurements of ultrafine particles and PM2.5 and their constituents (metals, PAHs, and other organics); including secondhand smoke (SHS) exposure; gases such as NO2, O3, SO2; a suite of volatile organic compounds (VOCs) including benzene, toluene, ethylbenzene, xylenes, acetaldehyde, formaldehyde, methylene chloride, and glycol ethers; microbiome, and a suite of allergens including dust mites, cockroach, cat, dog, and mouse allergens. Water samples from each residence will be analyzed for metals, pharmaceuticals, personal care products and pesticides, and transformation products that are formed in technical and natural treatment of water including disinfection byproducts.
- Plasma, serum, urine, and exhaled breath samples will be collected from each participant. Plasma, serum, and urine samples will be analyzed by high resolution MS and NMR for characterizing the metabolome and with ICP-MS for metals; serum samples will be used to characterize the transcriptome; epigenome; immunome; proteome and adductome.
- Chemical transport and satellite data prediction of PM/VOCs at each residential location.
- Dietary diaries and food samples, Socio-demographic and psychosocial information, time activity patterns, using mobile phone and GPS measurements.
Finding Non-genetic Causes for Childhood Asthma
The ultimate goal of The Exposome Collaborative Project 1 is to identify exposures that contribute to childhood asthma, especially among those internal and external exposures which have not been previously evaluated as risk factors for the disease. To this end, Exposome Collaborative investigators will perform an Exposome-Wide Association Study. Chemical features and biomarkers that contribute to asthma severity will be identified and their exposure sources will be determined. Finally, we will also work to communicate our findings in a meaningful way to those to which they matter the most.
- Carroll W. Asthma genetics: pitfalls and triumphs. Pediatric respiratory reviews. 2005;6(1):68-74. Epub 2005/02/09. doi: 10.1016/j.prrv.2004.11.007. PubMed PMID: 15698819.