Project Highlight – Worker Exposure Monitoring in an Operational Mine

Project Description:Quality Environmental Services and Technologies (QUEST) performed worker exposure monitoring at an operating commercial mine in Colorado. The Mine Safety and Health Administration (MSHA) previously issued Metal and Non-Metal Health Inspection Procedures findings at the site. In response, QUEST conducted annual exposure monitoring from 2018 through 2021. We compared all monitoring data to MSHA permissible exposure limits (PELs) to evaluate compliance and worker protection.

Sampling and Analysis:QUEST evaluated four primary exposure conditions: noise, respirable dust, airborne silica, and diesel particulate matter (DPM). During each annual event, employees wore personal sampling equipment while working in typical operating conditions. Our team used noise dosimeters, personal air pumps, and static sampling apparatus to collect representative data. We then calculated time-weighted averages (TWA) and shift-weighted averages (SWA) to determine exposure levels for each job classification.

Conclusions:Throughout the monitoring period, QUEST identified exceedances in both noise exposure and respirable DPM. Based on these findings, we recommended enrollment in a Hearing Conservation Program (HCP) and implementation of respiratory protection measures. Additionally, our analysis highlighted exposure differences between miners and drivers at the project site. Ultimately, QUEST provided clear documentation to support medical surveillance, PPE selection, and ongoing compliance efforts.