Ben Giudice

Civil and Environmental Engineering

Degree Objective: MS, PhD

Started in 2005

BSE, Civil Concentration, Calvin College, 2005

MS, Environmental Engineering, University of California Davis, 2007

 

Family: Wife Mary

Interests: The Environment, Fly Fishing, Woodworking, Football, the Outdoors

 

Research Projects

Roadside Herbicide Use in California: Modeling and Approaches

 

The California Department of Transportation (Caltrans) is one of the largest users of pesticides in the state.  Caltrans applies herbicides along highway roadsides to improve driver visibility, reduce the risk of fire, and prevent damage to the road surface.  Beginning in the early 1990’s, in response to public outcry against this practice, Caltrans set goals to reduce herbicide use by 50% of 1992 levels by 2000 and 80% by 2012.  As part of this effort, a study was conducted in which herbicides were analyzed in highway runoff and their transport characterized by sorption effects.  Following this, a model was developed that could predict the concentration in the runoff based on a number of physical-chemical parameters of an application at a site. 

My research uses this model to gain insight into the relative risks of application practices and the effectiveness of mitigation efforts and reducing these risks.  I first applied this model to the entire state of California using a Monte-Carlo technique and compared the results to toxicological endpoints.  This was a way to characterize relative risks of various site, chemical, and application characteristics.  I used the results of this study to investigate how effective different reduction efforts would be in reducing environmental risk.  Finally, I examined specific chemicals that showed signs of exhibiting less environmental risk were by conducting laboratory sorption experiments using soil from the highway roadside.  The chemical parameters gathered will be used in a future experiment that will attempt to validate the fate and transport model.  

 

 

The reproductive and population-level impact of environmental endocrine disruption on the invasive gastropod Potamopyrgus antipodarum

 

Over the last fifteen years, endocrine disrupting chemicals (EDCs) have become a topic of intense research.  EDCs enter natural waters such as rivers and lakes from many sources, including wastewater treatment plant (WWTP) discharges.  Even when present at very low levels, EDCs affect plants and animals in significant but unpredictable ways.  One such animal is the invasive Potamopyrgus Antipodarum (New Zealand Mudsnail), which has infested many waters of the Western US over the last 20 years.  This snail increases reproduction when exposed to EDCs that mimic estrogen in their bodies and decreases reproduction when exposed to EDCs that mimic male reproductive hormones, called androgens. 

In this study, the effects on this snail of these chemicals in mixtures, such as would be seen in the environment, will be studied in the laboratory.  Furthermore, long term population studies will be conducted to understand how effects manifest themselves to future generations.  Next, caged populations will be placed in parts of a river that contain WWTP discharge and parts that don't, and the effects of the discharge and the levels of EDCs in the water will be related to the reproductive effects seen.  From these experiments, it is hoped that population level effects of EDCs will be able to be predicted for environmental exposure scenarios.  The goal is that by better understanding the considerable effects of these chemicals, new regulations will be developed to protect our waters.  Furthermore, the project will add insight to potential effects of multiple environmental threats acting in concert, namely chemical contaminants and invasive species. 

New Zealand Mudsnails on a stream cobble.  Densities in the environment can reach approximately 1 million snails per square meter. 

(photo credit: D.L. Gustafson)