Biological Effects of Surfactants

Abstract

Summary Relative phytotoxicity of purified, biodegradable surfactants was determined by observing their effects on the growth of orchid seedlings in vitro. Pronounced phytotoxic effects occurred on culture media containing high concentrations of surfactants. Concentration of ionies above 100 ppm were most damaging and also caused a 90% or greater reduction of interfacial tension. Nonionic ethoxylates reduced growth and viability at lower concentrations than ionies, but larger percentages of seedlings survived at 1000 ppm levels of these agents, which were less efficient in reducing interfacial tension. No correlation was found between biological effects and surface tension data but a coincidence may exist between interfacial tension reduction by ethoxylates and increased phytotoxicity. A number of purification procedures for surface active agents are presented as an Appendix.

Biological Effects of Surfactants

“…Based on our findings with polar lipid-surfactant interfaces (Ernst et al, 1971), and the correlation between increase of surfactant concentration and phytotoxicity we suggest that the highly polar lipids of cytomembranes emulsify as concentration is increased. A change of the type induced by surfactants in interfacial tension may lead to changes in membrane permeability brought about by micellar rearrangements (Seufert, 1965).…”

“…No observable ultrastructural changes occurred in protocorms treated for 5 days with the nonionic LDA but it did bring about growth retardation and killing after several months (Ernst et al, 1971). This indicates that it does not damage the tissues for a considerable length of time although its actual activity may have been lowered by partial insolubility since stratification of this surfactant in agar-free culture medium was observed.…”

“…Alice Gloria xPhalaenopsis cv. Francine were grown on Knudson C culture medium (Knudson, 1946) as described previously (Ernst et al, 1971;Ernst and Arditti, 1968) and transferred to test and control media for periods ranging from I .2 hours to 5 days.…”

Biological effects of surfactants, IV. Effects of non-ionics and amphoterics on HeLa cells

“…4). Data presented here and in prior work from our laboratory [1,12,13] point to the physical (surface active) effects of detergents as a principal cause of their toxicity. Furthermore, these results show that HeLa cells are a sensitive cell line for assay of surfactant effects.…”

Dowanol, an Environmentally Safe Adjuvant

“…The adjuvants are surface active agents with a wide range of applications as wetting agents, detergents, emulsifiers, spreading agents, dispersants, foam reducers, solubilizers and penetrants. As the exact concentration of the components in herbicide/pesticide chemical formulations is not revealed by many of the manufacturers, surfactants have often been used carelessly and at concentrations greater than those required for their maximum efficiency as surface tension reducers [2]. Consequently, their use has generated potential ecotoxicity to a wide gamut of aquatic and terrestrial organisms [6,7].…”