PhD Proposal: Azmat Naseem

The Christina River, a vital waterway in Delaware, continues to face significant ecological and public health risks from legacy contaminants such as PCBs, PAHs, and organochlorine pesticides. Despite extensive monitoring and localized remediation efforts, critical knowledge gaps limit effective management. Traditional approaches depend on bulk water and sediment concentrations, which overestimate bioavailability, lack seasonal and spatial resolution, and thereby fail to capture the direct association between sediment contamination and subsequent increase in fish tissue burdens. Source contributions remain poorly understood, and existing models rarely integrate site-specific, bioavailable concentration data, limiting their predictive power for remediation decisions. 

 

This research tackles existing gaps through three interconnected goals: (1) Measure bioavailable contaminants by assessing freely dissolved PCB concentrations in surface water and porewater in multiple seasons with time-integrated passive sampling, which offers spatially heterogeneous data on bioavailability. (2) Use Positive Matrix Factorization (PMF) to identify and apportion sources of contamination, and (3) Develop a coupled fate–transport and food-web bioaccumulation model for scenario-based remediation evaluation.  

 

This research will improve predictions of fish tissue burdens, reduce uncertainty in risk assessments, and provide a decision-support framework to direct targeted remediation in the Christina River and comparable tidal systems.  

Location: WEBEX

 

WEBEX Meeting for virtual attendance: 

https://umbc.webex.com/umbc/j.php?MTID=m13332472bfa4584db4661488eb9b710b

Meeting number (access code): 2867 283 8560

Meeting password: 8zAyJSTZJ74