Intracellular space is at a premium due to the high concentrations of biomolecules and is expected to have a fundamental effect on how large macromolecules move in the cell. Here, we report that crowded solutions promote intramolecular DNA translocation by two human DNA repair glycosylases. The crowding effect increases both the efficiency and average distance of DNA chain translocation by hindering escape of the enzymes to bulk solution. The increased contact time with the DNA chain provides for redundant damage patrolling within individual DNA chains at the expense of slowing the overall rate of damaged base removal from a population of molecules. The significant biological implication is that a crowded cellular environment could influence the mechanism of damage recognition as much as any property of the enzyme or DNA.

Private wells serving fewer than 25 people are federally unregulated, and their users may be exposed to naturally occurring agents of concern such as arsenic and radionuclides, as well as anthropogenic contaminants. The Centers for Disease Control and Prevention's Clean Water for Health Program works to protect private wells and prevent adverse health outcomes for the roughly 15% of Americans who rely on them. To understand current and emerging challenges to the private drinking water supply, an interdisciplinary expert panel workshop on "Future and Emerging Issues for Private Wells" was organized to inform strategic planning for the Clean Water for Health Program. The panel assessed current conditions of ground water as a source for private wells, identified emerging threats, critical gaps in knowledge, and public health needs, and recommended strategies to guide future activities to ensure the safety of private drinking water wells. These strategies addressed topics of broad interest to the environmental public health community including: development of new methods to support citizen science; addressing contaminant mixtures; expanding capacity for well testing; evaluating treatment technologies; building an evidence base on best practices on well owner outreach and stewardship; and research and data needs.