Airborne transmission pathway for coastal water pollution

Possibly pathogenic bacteria in aerosols and foams as a result of aeration remediation in a polluted urban waterway

Newtown Creek is a tributary of the Hudson River Estuary. It has a legacy of both industrial pollution and sewage pollution and has been designated a Superfund site. To ameliorate the chronically low levels of dissolved oxygen detected in the Creek, the New York City Department of Environmental Protection has been installing aerators. The abundance of various bacteria in the aerosols, foams, and water, at two sites in the Creek, was studied before, during, and after the aeration process. Additionally, aerosols and dispersed foams created by the aeration process were sampled and cultured to determine what unique taxa of bacteria could be grown and identified. Taxa including Actinobacteria and Firmicutes were prevalent in cultures taken from aerosols, whereas Gammaproteobacteria were prevalent in cultures taken from foam. Campylobacteria was found to have a significant presence in both samples taken after the aerators were turned off. These taxa include potentially pathogenic bacteria and are therefore of particular concern.

Bacterial and Chemical Evidence of Coastal Water Pollution from the Tijuana River in Sea Spray Aerosol

Roughly half of the human population lives near the coast, and coastal water pollution (CWP) is widespread. Coastal waters along Tijuana, Mexico, and Imperial Beach (IB), USA, are frequently polluted by millions of gallons of untreated sewage and stormwater runoff. Entering coastal waters causes over 100 million global annual illnesses, but CWP has the potential to reach many more people on land via transfer in sea spray aerosol (SSA). Using 16S rRNA gene amplicon sequencing, we found sewage-associated bacteria in the polluted Tijuana River flowing into coastal waters and returning to land in marine aerosol. Tentative chemical identification from non-targeted tandem mass spectrometry identified anthropogenic compounds as chemical indicators of aerosolized CWP, but they were ubiquitous and present at highest concentrations in continental aerosol. Bacteria were better tracers of airborne CWP, and 40 tracer bacteria comprised up to 76% of the bacteria community in IB air. These findings confirm that CWP transfers in SSA and exposes many people along the coast. Climate change may exacerbate CWP with more extreme storms, and our findings call for minimizing CWP and investigating the health effects of airborne exposure.