In vitro bioassays to evaluate complex chemical mixtures in recycled water.

With burgeoning population and diminishing availability of freshwater resources, the world continues to expand the use of alternative water resources for drinking, and the quality of these sources has been a great concern for the public as well as public health professionals. In vitro bioassays are increasingly being used to enable rapid, relatively inexpensive toxicity screening that can be used in conjunction with analytical chemistry data to evaluate water quality and the effectiveness of water treatment. In this study, a comprehensive bioassay battery consisting of 36 bioassays covering 18 biological endpoints was applied to screen the bioactivity of waters of varying qualities with parallel treatments.

Reproductive responses of common carp (Cyprinus carpio) exposed in cages to influent of the Las Vegas Wash in Lake Mead, Nevada, from late winter to early spring.

The Las Vegas Wash (LW) delivers tertiary-treated municipal wastewater effluent, nonpotable shallow groundwater seepage, and runoff from the urbanized Las Vegas Valley to Las Vegas Bay (LX) of Lake Mead. To investigate the potential for contaminants in LW influent to produce effects indicative of endocrine disruption in vivo, adult male and female common carp (Cyprinus carpio) were exposed in cages for 42-48 d at four sites in Lake Mead: LW, LX, and two reference locations in the lake. End points examined included gonadosomatic index; gonad histology; concentrations of plasma vitellogenin (VTG) and plasma sex steroids (17beta-estradiol (E2), testosterone (T), 11-ketotestosterone (11-KT)); plasma estrogen:androgen ratios (E2:T, E2:11-KT), in vitro production of T by gonad tissue, and hepatopancreas ethoxyresorufin O-deethylase activity.

Examination of reproductive endpoints in goldfish (Carassius auratus) exposed in situ to municipal sewage treatment plant effluent discharges in Michigan, USA.

Effects of representative mid-Michigan (USA) wastewater treatment plant (WWTP) effluents on the reproductive physiology of common goldfish (Carassius auratus) were assessed in situ by measuring plasma concentrations of vitellogenin (VTG), 17 beta-estradiol (E2), and testosterone (T), and evaluating gonad histology. Caged adult male and female goldfish were exposed for six weeks to WWTP effluents. One riverine site and one lacustrine site were included as references for comparison to WWTP sites.

An evaluation of irritant smoke to detect exhalation valve leakage in respirators.

This study evaluated the ability of a qualitative fit-test method (irritant smoke) to detect known exhalation valve leakage. The OSHA protocol for the irritant smoke test mandates the use of a low flow air pump at 200 mL/minute or an aspirator squeeze bulb. Many commercial test kits include an aspirator bulb, which is subject to variation in frequency, depth of squeeze, fatigue rate, and individual hand strength.