How quickly can ultraviolet light potentially destroy DNA evidence?

Ultraviolet (UV) light can quickly degrade DNA evidence, making it a significant concern for forensic investigators. The correct choice indicates that DNA can be damaged in as little as 30 seconds of exposure to UV light. This rapid degradation occurs because UV radiation generates free radicals and other reactive species, which can break down the molecular structure of DNA and lead to the formation of pyrimidine dimers—specific types of errors in the DNA structure.

While DNA can certainly be affected in shorter time spans, the 30-second mark captures the critical threshold where significant damage can begin to occur and highlights the importance of protecting DNA evidence from UV exposure during the collection and analysis phases. Understanding this time frame enables crime scene investigators to implement measures to preserve DNA samples, ensuring the integrity of the evidence for later examination.

In contrast, while other options suggest longer durations, they do not emphasize the immediacy with which UV light can compromise DNA integrity, which is crucial for those working in forensic science and crime scene investigation.