Background: Over the past 10–15 years, a substantial amount of work has been done by the scientific, regulatory, and business communities to elucidate the effects and risks of pharmaceuticals and personal care products (PPCPs) in the environment.Objective: This review was undertaken to identify key outstanding issues regarding the effects of PPCPs on human and ecological health in order to ensure that future resources will be focused on the most important areas.Data sources: To better understand and manage the risks of PPCPs in the environment, we used the “key question” approach to identify the principle issues that need to be addressed. Initially, questions were solicited from academic, government, and business communities around the world. A list of 101 questions was then discussed at an international expert workshop, and a top-20 list was developed. Following the workshop, workshop attendees ranked the 20 questions by importance.Data synthesis: The top 20 priority questions fell into seven categories: a) prioritization of substances for assessment, b) pathways of exposure, c) bioavailability and uptake, d) effects characterization, e) risk and relative risk, f ) antibiotic resistance, and g) risk management.Conclusions: A large body of information is now available on PPCPs in the environment. This exercise prioritized the most critical questions to aid in development of future research programs on the topic.

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Abstract-In the Chironomus tentans 10-d growth test, changes in larval growth relative to sediment contamination are often ascribed ecological relevance by assuming that such changes become manifest at the population level through effects on reproductive output even though the relationship between growth and reproduction is poorly understood. The objective of this study was to evaluate the relationship between growth and reproduction in C. tentans and to use these data in a demographic model to predict the growth and size of a theoretical population. Growth was manipulated by varying food supply (0.29, 0.33, 0.38, 0.42, 0.46, and 0.5 mg/individual per d). The test was initiated with 12 newly hatched larvae per replicate and carried through one complete generation. Larval growth and survival were determined at 20 d, and reproduction was monitored daily during emergence. Food supply did not significantly affect survivorship at any life stage; survival of larvae at 20 d, pupae, and adults exceeded 83%, while survival of larvae in the reproduction replicates exceeded 65%. Both larval and adult dry weight declined significantly with a reduction in food supply. Total emergence was reduced at the lowest feeding level only, whereas the rate of emergence declined at food supplies below 0.42 mg/individual per d. Based on the relationship between larval and adult dry weight, a minimum larval tissue mass of between 0.5 and 0.6 mg dry weight/individual appears to be necessary before emergence can take place. The number of eggs/female declined significantly with a decrease in food supply below 0.42 mg/individual per d. Above this level (corresponding to larval dry weight of ϳ 1.5 mg/individual), the addition of more food had no effect on reproductive output. Fecundity (number of daughters/female) and expected number of progeny declined linearly with reduced food supply. Application of the data in a demographic model showed that the growth and predicted size of a population would decline significantly with a decline in larval growth and reproductive output. These results demonstrate that changes in growth, positive or negative, can be used to make meaningful predictions regarding reproduction and population dynamics in the midge C. tentans.

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Abstract-The development and standardization of toxicity test methods for assessing toxicity of contaminated freshwater sediments has focused predominantly on short-term exposures and lethality. In many situations, however, toxicity is more likely to become manifest over long periods of time so there is need for standardized testing procedures by which sublethal sediment toxicity can be adequately assessed. In this study, we present and evaluate a new life cycle test, using the midge Chironomus tentans, which enables the assessment of sublethal toxicity of contaminated sediments. In designing the life cycle test, our goal was to make the assay relatively straightforward and, to the extent possible, methodologically compatible with the standard 10-d test. The test is initiated with newly hatched (Ͻ24 h) larvae and uses four effects-based endpoints to assess toxicity: survival, growth, emergence, and reproduction. Survival is determined at 20 d and at the end of the test by back-calculating through emergence data. Growth can be determined at 20 d, which corresponds to the 10-d endpoint in the 10-d C. tentans growth test initiated with 10-d-old larvae. From day 23 to the end of the test, emergence and reproduction are monitored daily. The number of eggs per female is determined for each egg mass, which is then incubated for 6 d to determine hatching success. Each treatment in the life cycle test is terminated separately after 7 consecutive days without emergence. We evaluated the life cycle test by following one generation of C. tentans in sediments collected from the upper Mississippi River. Survival of larvae exceeded 90% at 20 d. Of these larvae, between 60 and 70% successfully emerged; survivorship among pupae and adults exceeded 85%. Mean egg production ranged from 906 to 1,107 eggs per female. The test required 65 d to complete, including pretest preparation. These data show that the C. tentans life cycle test can be used to assess sublethal toxicity accurately in contaminated sediments and provides a suitable compliment to the standard C. tentans 10-d test.