Soil pollution by nonylphenol and nonylphenol ethoxylates and their effects to plants and invertebrates

Abstract

Background, aim, and scope Nonylphenol polyethoxylates (NPEOs) are a widely used class of nonionic surfactants known to be toxic and endocrine-disrupting contaminants. Their use and production have been banned in the European Union and substituted by other surfactants considered as environmentally safer. However, their use continues in many countries without any legal control. Discharges of effluents from wastewater treatment plants and the application of sewage sludge application, landfilling, and accidental spillage to soils are the major sources of NPEOs in the environment. The biodegradation of these surfactants is relatively easy, leading to the accumulation of the simplest chemical forms of nonylphenol ethoxylates (NP, NP1EO, and NP2EO) and nonylphenol carboxy acids (NP2EC or NP1EC). However, these are also the most toxic end-products and have a higher environmental persistence. Compared to aquatic ecosystems, not much is known about the effects of NPEOs in terrestrial organisms, with few studies mainly centered on the effects on plants and soil microorganisms. The main aim of this study is to provide the range of concentrations of NPEOs with ecotoxicological effects on different plants and soil invertebrate species. In addition, we aim to identify the main soil properties influencing their toxicity.Materials and methods Two natural soils collected and OECD artificial soil were used in toxicity bioassays. Two different NPEO formulations were tested. On the one hand, a technical mixture of NPEOs containing chain isomers and oligomers with an average of eight ethoxy units was used for the experiments and is referred to herein as NP8EO. On the other hand, technical-grade 4-nonylphenol 95% purity was also used and called NP in this study. The chemicals were applied and mixed with soil as an acetone solution. The toxicity of NP8EO and NP was assessed in different taxonomical groups (plants, earthworms, enchytraeids, and collembolans) according to their respective standardized methods. The effect on lethal and sublethal endpoints was assessed and, by means of linear and non-linear regression models, the NPEO concentration causing 10% and 50% inhibition was estimated. The influence of soil properties on the toxicity was assessed using generalized linear models (GLM). Results The chemicals tested showed contrasting toxicities, NP being clearly more toxic than NP8EO. There were also substantial differences in the sensitivity of the species and endpoints, together with clearly different toxicities in different soils. Plants were the least affected group compared to soil invertebrates, since plant endpoints were unaffected or only slightly inhibited. In soil invertebrates, reproduction was the most affected endpoint compared to growth or survival. Toxicity was the lowest in OECD artificial soil in comparison to natural soils, with a lower organic matter content. Discussion The higher toxicity of NP, both in plant and soil invertebrate bioassays, is consistent with previously published studies and its relatively high p...

Phytodecontamination of Water Systems from Phenolic Endocrine Disruptors and the Regulation Role of Natural Organic Matter

“…[45] with Lolium perenne and Brassica rapa. In water added with HA at the two doses, the removal of NP measured by ryegrass and radish was significantly higher than that found in water only, and this positive effect could be attributed to its stimulation of plant enzymatic activity, as previous shown by Nardi et al [46] and Vaughan et al [47].…”

“…Some plant species used in phytoremediation from phenolic endocrine disruptors are referred in Table 1. Raphanus sativus, Lolium perenne 17α ethynilestradiol [40] Portulaca oleracea 17β estradiol [53] Portulaca oleracea octylphenol [53] Crested wheatgrass 4-Nonylphenol [44] Lolium perenne, Brassica rapa 4-Nonylphenol [45] Lupinus spp.…”

Effects of nonylphenol on a soil community using microcosms

“…Several studies have reported toxic effects on aquatic fauna (Lussier et al 2000;Staples et al 2004;Soares et al 2008), partly due to the fact that NPEOs mimic estrogen compounds, interfering in the action of endogenous hormones by binding to the estrogen receptor and eliciting a biological response resulting in endocrine disruption (Quinn et al 2006). However, and despite the usual presence of NPEOs in soils, not much is known about their effects on terrestrial organisms in comparison to aquatic organisms, and the available data are restricted to their effects on plants and microorganisms (Gejlsbjerg et al 2001;Dettenmaier and Doucette 2007;Domene et al 2009). NPEOs have also been demonstrated to have toxic effects on mammals (de Jager et al 1999;Ferguson et al 2000), and the few existing studies have shown noxious effects on soil nematodes (Hood et al 2000), earthworms, enchytraeids, and collembolans (see Domene et al 2009 and references therein).…”

“…However, and despite the usual presence of NPEOs in soils, not much is known about their effects on terrestrial organisms in comparison to aquatic organisms, and the available data are restricted to their effects on plants and microorganisms (Gejlsbjerg et al 2001;Dettenmaier and Doucette 2007;Domene et al 2009). NPEOs have also been demonstrated to have toxic effects on mammals (de Jager et al 1999;Ferguson et al 2000), and the few existing studies have shown noxious effects on soil nematodes (Hood et al 2000), earthworms, enchytraeids, and collembolans (see Domene et al 2009 and references therein). In addition, no data regarding the effects on soil invertebrate communities as a whole have been published to date.…”

“…In addition, no data regarding the effects on soil invertebrate communities as a whole have been published to date. In a previous study, we addressed the direct effects on soil invertebrates of NPEOs using isolated species with asexual reproduction, concluding that these compounds have low toxicity for soil invertebrates (Domene et al 2009). In this study, we choose a microcosm approach for the assessment of the effects of NPEOs on soil organisms.…”