Hazardous Working Conditions
Archaeological sites within a city can contain many potential hazards. Sometimes these hazards lie in the activities on the site itself: heavy machinery, open trenches, loud and constant noise. Other times the hazards can be unseen. Many city sites are contaminated by lead and other heavy metals from leaded gas emissions, leaking underground fuel tanks or previous industrial development. Historical catastrophes can also play a role. For instance, in San Francisco many city blocks were used as dumping areas for debris left from the 1906 Earthquake and subsequent fire. These blocks are often contaminated with high lead levels from old lead pipes and paints. In addition, the process of archaeological excavation itself can present hazards. The features being excavated can often be deep and located in unstable soils or sand that are prone to collapsing on the excavator. Excavations can also involve working in very confined spaces.
Archaeologists prepare for such conditions by testing the site, training, and taking precautionary measures, such as using protective clothing and equipment. The activities on an archaeological site in California are governed by the safety requirements of the California Occupational Safety and Health Act (CAL/OSHA). Before excavation, a site in the city is tested to see whether it might contain any hazardous materials such as heavy metals.
On the majority of city sites, particularly those involving any type
of heavy equipment or construction activities, the minimum personal
equipment that the archaeologist requires is a hard hat, bright-colored
safety vest, long pants, strong boots and ear plugs. Additional precautions
for sites highly contaminated with lead or other heavy metals include
at least 40 hours of training in how to work safely in hazardous environments,
and possibly protective clothing such as white Tyvek suits and safety
glasses. Shoring equipment and techniques such as benching or stepping
the walls around an excavation area can be used if the archaeologist
must excavate beyond a safe depth.