Persistent Pollution of Genetic Materials in a Typical Laboratory Environment

Abstract

From the beginning of coronavirus disease (COVID-19) pandemic, the concerns regarding the disease spread and environmental pollution of biohazard were proposed since studies on genetic engineering flourish and numerous genetic materials were used such as the nucleic acid test of the severe acute respiratory syndrome coronavirus (SARS-CoV-2). In this work, we studied genetic material pollution in an institute during a development cycle of plasmid, one of typical genetic materials, with typical laboratory settings. The pollution source, transmission routes, and pollution levels in laboratory environment were examined. The results of all environmental mediums (e.g. surface, aerosol, and liquid, etc.) showed that a targeted DNA segment occurred along with routine experimental operations. Persistent nucleic acid contaminations were observed in all tested laboratories and spread in the public area (hallway). The highest concentration for liquid and surface samples were 1.92×108 copies/μL and 5.22×107 copies/cm2, respectively. Significant amounts of targeted gene (mean value of 74 copies/L) were detected in the indoor air. Inadvertent spills and improper disposals of plasmid products are major sources of pollution. The importance of deploying an experimental zone, advanced biosafety cabinets, and high efficient cleaning systems for laboratories of low biosafety levels is highlighted.

Keywords: Pollution of genetic materials, laboratory experiment, indoor environment, pollution assessment