Toxicity Reduction Evaluation, Toxicity Identification Evaluation and Toxicity Tracking in Direct Toxicity Assessment

Abstract

Toxicity reduction evaluations (TREs) in the River Esk and Lower Tees Estuary were based on the approach described by USEPA, but adapted to tackle the specific problems of the two sites. A combination of toxicity tracking and toxicity identification evaluation (TIE) was used at both locations to enhance the understanding of source and type of toxicants present. The assessment of toxicity at Langholm focussed on pesticides present in the sewerage network. The TIE programme indicated that the most likely toxic agents within the effluent were the organophosphate pesticides diazinon and to lesser extent propetamphos, although these did not account for all of the observed toxicity. The exact source of these toxicants was not clear although toxicity tracking identified two potential candidates. The TRE undertaken on the discharge to the lower Tees utilised high-throughput methods with standard test organisms to generate toxicity information throughout a complex sewerage network. The toxicity tracking information was used in conjunction with TIEs to identify a number of key sources of toxicity. Substantial toxicity was associated with a currently untreated industrial effluent. Chemical analysis and TIE highlighted cyanide as the likely toxicant in this effluent and its possible significance in the final discharge.

Application of toxicity identification evaluation procedure to toxic industrial effluent in South Korea

“…Nonylphenol is a degraded product of nonylphenol ethoxylate and is widely observed in effluents at concentrations of several hundred lg/L (Lee and Peart, 1995;Höhne and Püttmann, 2008). It has been occasionally traced as a toxicant that causes effluent toxicity (Hutchings et al, 2004). Two other phenolic compounds Table 6 Organic compounds identified by GC/MS and LC/MS in effluents.…”

“…Additionally, alkane compounds are the second highest toxic chemical group that contributes to total effluent toxicity, including tetratriacontane, ecosan, nonadecane, octadecane, and heptadecane. Regarding industrial characteristics, no organophosphorous pesticides, such as diazinon or chlorfenvinphos, which are frequently observed toxicants in municipal wastewater treatment plants, were observed in the target effluent (Hutchings et al, 2004;Bailey et al, 2005). Considering that the wastewater was discharged from a pharmaceutical manufacturing plant, it was expected that many pharmaceuticals or pharmaceutical-related compounds would exist in the effluent.…”

Finding biomarkers is getting easier

“…4. The protein variables need to be identified after they have been confirmed statistically (Ankley et al 2006;Fairbrother 2009;Hutchinson 2007;Miracle and (Tinsley et al 2004;Hutchings et al 2004). In the same issue Crane et al (2004) show how risk assessment based on probabilities is very effective when all available data are used.…”

Are Pseudokirchneriella subcapitata and Chlorella vulgaris Affected by Environmental Samples from a Rice Field?

“…WET and similar toxicity tests integrate interactions among complex mixtures of contaminants (Chapman 2000;Wharfe 2004;Wharfe et al 2004). They measure the total toxic effect, regardless of physical and chemical composition (Chapman 2000), being considered effective tools for predicting instream impacts induced by different kinds of contamination sources (Ausley 2000;de Vlaming et al 2000;Diamond and Daley 2000;Hutchings et al 2004). Notwithstanding, similar procedures have already been applied in bioassays with sediment elutriates to evaluate their toxicity (Cheung et al 1997;Pardos et al 1998;Wong et al 1999;Baun et al 2002;Müller et al 2002), as sediment acts as a sink of contaminants, which can be exchanged between the sediment and the aqueous phase due to disposal, stormwater runoff and water turbulence (Ankley et al 1991;Mucha et al 2003), which is likely to occur during the drainage of rice fields.…”