Literature Review Summary 

Chemical Name: Atrazine 

PC Code: 080803 

Purpose of Review (DP Barcode or Litigation): 

Review for inclusion in the atrazine risk assessment 

Date of Review: 3/21/16 

Summary 

Syngenta submitted the following list of studies describing the isolation, culturing and testing for 

atrazine toxicity on the algae Oophila sp., an algae that forms a symbiotic relationship with some 

salamander species (MRIDs 49639109, 49639110, 49535803, 49535801, 49639104). The reviewer 

read the following study reports provided to the agency and considered their science and reported 

results: 

Baxter, L.; Brain, R.; Rodriguez-Gil, J.; et al. (2014) Atrazine: Response of the Green Alga Oophila

sp., a Salamander Endosymbiont, to a PSII-Inhibitor under Laboratory Conditions. Environmental 

Toxicology and Chemistry 33(8):1858-1864. MRID 49535803 

Hanson, M.; Rodriquez-Gil, J.; Baxter, L.; et al. (2014) Isolation, Identification, and Optimization 

of Culturing Conditions of the Alga Oophila sp., a Salamander Symbiont, for its Use in Toxicity 

Testing under Laboratory Conditions: Final Report. Project Number: ATZ2013B, TK0186283. 

Unpublished study prepared by University of Guelph. 30p., MRID 49639109 

Hanson, M.; Baxter, L.; Rodriquez-Gil, J.; et al. (2014) Characterization of the Response of the 

Alga Oophila sp., a Salamander Symbiont, to Atrazine Under Laboratory Conditions: Final Report. 

Project Number: ATZ2013A, TK0186283. Unpublished study prepared by University of Guelph. 

52p., MRID 49639110 

Hanson, M.; Baxter, L.; Solomon, K. (2015) The Response of the Salamander Ambystoma 

maculatum and its Egg-Capsule Endosymbiont (the alga Oophila sp.) to the Photosystem II 

Inhibitor Atrazine Under Laboratory Conditions: Final Report. Project Number: ATZ2014, 

TK0224041. Unpublished study prepared by University of Guelph. 103pp. MRID 49639104 

Rodriguez-Gil, J.; Baxter, L.; McConkey, B.; et al. (2014) Atrazine: Optimization of Culturing 

Conditions for Toxicity Testing with the Alga Oophila sp. (Chlorophyceae), An Amphibian 

Endosymbiont. Environmental Toxicology and Chemistry 33(11):2566-2575. MRID 49535801 

Reviewer Conclusions: 

These studies are relevant to the potential effects due to atrazine environmental exposures and were 

submitted to address the identification of these effects as a potential risk concern in the 2012 SAP 

Problem Formulation for Atrazine (Oliver et al. 2010). A brief review of the study results indicate that 

the direct effects on the salamander eggs or algae do not result in more sensitive endpoints and thus 
would not contribute new data for refinement of current amphibian or non-vascular plant endpoints 

used in the risk assessment. Therefore these studies were not fully reviewed for inclusion in the risk 

assessment. If, at a later time, these data are to be utilized for regulatory decision making, then a 

complete review of the studies should be conducted at that time. 

Primary Reviewer: Frank T. Farruggia, Ph.D. Biologist ERB3 

Digitally signed by FRANK FARRUGGIA 

DN: c=US, o=U.S. Government, 

ou=USEPA, ou=Staff, cn=FRANK 

FARRUGGIA, dnQualifier=0000048865 

Date: 2016.04.29 09:59:24 -04'00'