Linking algal growth inhibition to chemical activity: Excess toxicity below 0.1% of saturation.
Chemosphere
; 208: 880-886, 2018 Oct.
Article
em En
| MEDLINE
| ID: mdl-30068031
ABSTRACT
Chemical activity quantifies the energetic level of an organic compound relative to its pure liquid [0-1], and several studies have reported that baseline toxicity generally requires chemical activities of 0.01-0.1. The first aim was to challenge this chemical activity range for baseline toxicity. Algal growth inhibition data (median effective concentrations, EC50) were compiled from two recent studies and included 108 compounds categorised as non-polar (mode of toxic action, MOA1) and polar (MOA2) narcotics. These data were linked to chemical activity by (1) plotting them relative to a regression for (subcooled) liquid solubility (SL), which served as visual reference for chemical activity of unity and (2) determining EC50/SL ratios that essentially equal median effective chemical activity (Ea50). Growth inhibition required chemical activity >0.01 for MOA1 and >0.001 for MOA2 compounds. The second aim was to identify compounds exerting excess toxicity, i.e., when growth inhibition occurred at chemical activity <0.001. From a recent review with 2323 data entries, 315 EC50 values passed our selection criteria. 280 of these EC50 values were within or near the baseline toxicity range (Ea50>0.001), and 25 compounds were found to exert excess toxicity (Ea50<0.001). Of these compounds, 16 are pesticides or precursors. Methodologically, this study includes two methods for translating EC50 values into the chemical activity framework, each having advantages and limitations. Scientifically, this study confirms that baseline toxicity generally requires chemical activities of 0.01-0.1 and extends the application of the chemical activity approach beyond baseline toxicity, by demonstrating its utility to identify compounds that exert excess toxicity.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos Orgânicos
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Poluentes Químicos da Água
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Testes de Toxicidade
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Clorófitas
Tipo de estudo:
Prognostic_studies
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Risk_factors_studies
Idioma:
En
Revista:
Chemosphere
Ano de publicação:
2018
Tipo de documento:
Article
País de publicação:
ENGLAND
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ESCOCIA
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GB
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GREAT BRITAIN
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INGLATERRA
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REINO UNIDO
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SCOTLAND
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UK
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UNITED KINGDOM