Micro-MOOP: A Study of the Anthropocene in the Black Rock Desert

Black Rock City (BRC) is a temporary city that exists for two weeks every year in the remote Black Rock Desert in Northern Nevada, USA. BRC is the largest leave no trace city in the world, meaning, after its existence everything that is visible to the human eye is removed from the desert surface. Anything left behind is considered MOOP or Matter out of Place. Anything smaller than about 100 micrometers is left behind as micro-MOOP. BRC was used as a case study to estimate human exposure to respirable microplastic pollution created from human activities such as driving cars, wearing synthetic clothing, construction, and the process of urbanization. BRC is a highly controlled environment where population size, number of registered vehicles, city land area, and other city statistics are recorded and published. The Black Rock Desert is renowned for its fine dust particles, which can be easily captured using atmospheric dust collectors such as the USGS marble (MDCO) and the modified Wilson and Cooke (MWAC) dust collectors. These dust collectors can be used to determine dust flux or transport. Atmospheric dust samples have been collected from the Black Rock Desert using the MDCO and MWAC samplers before, during, and after the construction/deconstruction of BRC and analyzed via FTIR and Raman spectroscopy for the presence of microplastics and micro-MOOP. An increase in microplastic fragments, fibers, spheres, and tire particles were found during urbanization of BRC. Performing LC/MS will identify the presence of toxic chemicals associated with micro-MOOP, such as PFAS (outdoor wear) and 6PPD-Quinone (tires). Human exposure via inhalation to such particles and chemicals will be estimated in this first of its kind study based on population size, city area, and microplastic transport.