# Presentation: 042305

## U.S. EPA Emerging Pollutants WorkshopNonylphenol and Nonylphenol Ethoxylates: Aquatic Toxicity, Estrogenicity and Treatability in Wastewater Effluent

- Charles A. Staples
- Ellen M. Mihaich
- Barbara S. Losey
- Chicago, IL
- August 11-14, 200.

## Background...

- Nonylphenol ethoxylate (NPE) surfactants are widely used in applications that are sent to sewage treatment plants when spent
- While NPEs are generally easily treatable in well run treatment plants, residues from biodegradation are often detectable in effluents
- It is of interest to examine the potential risks to the environment from these residues
- Risk assessment is the preferred means of addressing these compounds

## Background...

- Risk assessment requires:
- Exposure data
- Ecotoxicity data
- The results of risk assessment are used by risk managers to control and manage potential unwanted risks
- _Purpose_:
- Examine the ecotoxicity database, including endocrine-modulating effects, for the NPEs, NPEC, NP that are most common in effluents as shown in treatability studies

## Treatability studies of NPE surfactants...

- _Example_: Canadian STPs (receive municipal and industrial wastes)
- STP-A:
- activated sludge (2°), nitrification, tertiary (3°) treatment and UV disinfection
- removal efficiency of 97% for all species
- STP-B:
- non-nitrifying activated sludge (2°), chlorine disinfection
- removal efficiency of 86% for all species

## Treatability studies of NPE surfactants...

- Ahel and Giger (1994a,b), Lee and Peart (1998)
- main products in raw sewage are commercial NPE
- main components in final effluents were NPEC with some NPE1,2, and traces of NP
- Monitoring studies
- 30 Rivers Study
- NP & NPE1,2:  ~0.1 μg/L, NPE3-16:  ~ 2 μg/L
- USGS National Reconnaissance Survey
- NP, NPE1,2: medians 0.8 to 1.0 μg/L
- Risk assessments of NPE residues from STPs in surface water should encompass:
- NPEs, NPEC, NP

## Chronic aquatic toxicity of NP...

- Critical review of chronic aquatic toxicity data for NP and NPE
- Dozens of studies, endpoints, LOEC, NOEC
- Survival, growth, reproduction
- Manuscript to be submitted to International Journal of Human and Ecological Risk Assessment
- SSD analysis shows that the data support the draft USEPA WQC for NP (~5.9 g/L)

## Chronic aquatic toxicity of NP...

- All studies were subject to a quality review
- 1. Thorough description of: the experimental design, 		including test material identification and description, 	exposure regime and replication;
- 2.	Analytical confirmation of test concentrations;
- 3.	Description of all ecologically relevant endpoints and 	all supplemental secondary biochemical and 			morphological information collected, including a full 	description of how they are measured;

## Chronic aquatic toxicity of NP...

- All studies were subject to a quality review
- 	4. Use of test procedures that are based, at least generally, 	on internationally accepted procedures and practices, 	including both draft and final methods;
- 	5. Clear linkage of reported findings with the exact 		experimental design, and,
- 	6. Sufficient reporting of results, including system 		performance, adequacy of control performance, 		toxicity results, and statistical methods employed to 		ascertain how the data support the conclusions.

## + Survival ChV

- x Growth ChV
- □ Reproductive ChV
- Figure 1. Chronic values (ChV) for survival (+), growth (x) and reproduction (□) for fish (F), aquatic invertebrates (INV), and algae (ALG) by NPEx.

## Slide 10

## Determination of in vivo endocrine effects in fish from NPE and biodegradation metabolites

- Gordon Balch and Chris Metcalfe (Trent University, Peterborough, ON, Canada), February 2003
- Exposed medaka fish to NP, NPE1, NPE4, NPE9, NPEC1 from 1 to 100 days post-hatch
- Endpoints:
- sex ratio
- secondary sex characteristics
- liver VTG
- testis-ova

## Results...

## Study Results...

## Conclusions from medaka study...

- NP induced gonadal intersex and mixed secondary characteristics in male medaka at 30 and 100 g/L
- Mixed secondary sex characteristics were induced in males at 300 g/L NPE1
- No evidence of estrogenicity with NPE4, NPE9 or NPEC up to 1000 or 3000 g/L
- No effect on sex ratio for any compound

## Summary and Conclusions...

- Ecotoxicity studies show increasing toxicity with decreasing ethoxylation
- Ecotoxicity studies of NPECs show them to be relatively non-toxic
- Only NP showed estrogenic potential in a long-term developmental study with medaka
- Thus, the available database of conventional chronic studies should be adequate to address the ecotoxicity of the various biodegradation intermediates of NPE surfactants

## Summary and Conclusions...

- Treatability studies show that well run STPs are effective at removing NPE surfactants, but residues do enter receiving waters
- Risk assessments of surface waters receiving STP effluents should address all biodegradation intermediates
- Risk management to reduce risk from natural hormones  in human waste simultaneously addresses NPE, NP, NPEC
- Risk management to reduce risk from industrial sources should include Best Management Practices