Action Spectra

Exogenous indirect photoinactivation of bacterial pathogens and indicators in water with natural and synthetic photosensitizers in simulated sunlight with reduced UVB

“…The rate of photoinactivation and the mechanism via which it occurs are believed to vary with the relative intensities of UV and visible light. Past studies have found UVB to be primarily responsible for bacterial photoinactivation, with UVA and visible light playing minor roles (Calkins and Barcelo ). Photoinactivation of bacteria may occur via three different mechanisms: endogenous direct, endogenous indirect and exogenous indirect (Davies‐Colley et al .…”

Biological Weighting Functions for Evaluating the Role of Sunlight-Induced Inactivation of Coliphages at Selected Beaches and Nearby Tributaries

“…Studies of sunlight inactivation of bacteria in natural waters date back to the 1800s and show that photoinactivation occurs via a variety of pathways . Inactivation of FIB and other indicators upon exposure to solar ultraviolet (UV) radiation is a key determinant of their densities in aquatic environments. ,,− For example, sensitivity analysis using three-dimensional hydrodynamic and transport models indicates that, compared to all other loss processes, solar inactivation has the greatest impact on loss rates of E. coli at near-shore locations in southern Lake Michigan . A recent review by Nelson et al provides a wealth of information about sunlight-mediated inactivation of health-related microorganisms in natural and engineered systems …”