Loyola University Chicago

Department of Biology

Erik Reynolds Project Description

Chronic Effects of Lead Exposure on Atherinops affinis (Topsmelt): Influence of Salinity and Organism Age.


Lead (Pb) appears in the environment as a consequence of both natural and anthropogenic processes. Mining, smelting, coal burning, Pb acid batteries, and cement manufacturing substantially release Pb into aquatic environments. The goal of this study was to determine the influence of salinity and organism age on chronic toxicity of Pb to topsmelt (Atherinops affinis) in support of development of a species sensitivity distribution (SSD). Species sensitivity distributions assist in ecological risk assessments and establishing quality criteria for contaminants. Three chronic exposure studies were conducted for 28 days in a water flow-through testing system. Survival, standard length, dry weight, and tissue Pb concentration were measured and lethal concentrations (LCs), effective concentrations (ECs), and bioconcentration factor (BCF) were calculated. In general, increasing salinity and organism age decreased Pb toxicity. The 28-d LC50 values for larval fish at 14 and 28 ppt salinity were 15.14 and 79.84 µg/L dissolved Pb, respectively, whereas the 28-d LC50 was 167.6 µg/L dissolved Pb for juvenile fish at 28 ppt salinity. Using standard length, the EC10 values for larval fish were 16.63 and 82.30 µg/L dissolved Pb at low and high salinity, respectively. The dry weight EC25 for low and high salinity were 15.62 and 46.85 µg/L dissolved Pb, respectively. The BCF was higher (2.00) with lower salinity (0.73). This is likely due to competition between salt ions and Pb at biotic ligand binding sites as well as lowered Pb speciation rates. These results indicate the need for increased protection in more Pb sensitive lower salinity environments as well as continued government protection of Pb contaminant risk areas.                                                              

Keywords: Lead toxicity, growth effect, fish, bioaccumulation, lead speciation


I would like to first and foremost thank Dr. Tham Hoang for allowing me to work in his lab. He has been a great mentor, role model, and guide through both my undergraduate and graduate programs. From scientific conferences to late night emails he has facilitated my research and schooling in many ways. Without his guidance and suggestions, I don’t believe I would have ever enrolled in Loyola’s M.S in Biology Program. He has provided me with the skills and knowledge I need to succeed in my field and I couldn’t have asked for a better P.I. Secondly, I would like to thank Dr. Martin Berg for not only assisting in my thesis work but also being great mentor and professor to me. Lastly, Dr. Rodney Dale been a great committee member whose suggestions helped me plan and execute my thesis research studies. This research was made possible by Dr. Jasim Chowdry at the International Lead Zinc Research Organization. Thank you Dr. Chowdry for the funding. I would also like to thank the Biology graduate school for all the assistance and support.

I would also like to thank my Hoang laboratory members who provided me with help throughout my research. As a team, we accomplished great research projects, challenged one another, and have fun. I would like to thank those lab mates of mine who have contributed to my work: Edgar Perez, Patrick Caniff, Claudia Mroczkowski, Ritesh Kashyap, and Ellen Cole.

Finally, I couldn’t have truly completed any of this without the encouragement, love, and support from my family. I hope I have made them proud of what I have accomplished and continue to make them proud into the distant future.


Erik’s interest in biology, toxicology, and environmental science began during his undergraduate career at Loyola University Chicago. Upon completing his B.S. in environmental science, he began pursuing a master’s in Biology. His research focus has primarily been metal toxicities to aquatic and marine species. In addition to conducting toxicity tests, he oversaw cultures of fathead minnows, Florida apple snails, and water fleas in Dr. Tham Hoang’s Lab at Loyola University Chicago.         

Erik has presented his research at the 2015 Society of Environmental Toxicology and Chemistry national meeting regarding his research chronic Pb marine exposures. He plans to pursue a position in industry upon finishing his degree. 

Committee Members

Dr. Tham Hoang

Dr. Martin Berg

Dr. Rodney Dale