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Relatively little work has been done on the role of micronutrients in influencing development and progression of harmful algal blooms, yet micronutrients are ineluctably required for growth. Relatively small changes in micronutrient status have wide-ranging consequences. Here, we report results from mesocosm experiments with Microcystis and Desmodesmus spp., in mono- and mixed-cultures, to probe questions of how copper, iron, and copper-iron amendments affect growth, short-term assemblage progression, and production of siderophore, chalkophore, and microcystin in lake water from a large, hypereutrophic lake (Taihu, China). Our approach offers an entirely new perspective to understanding micronutrient dynamics in aqueous environments, as this is the first work to systematically screen for chalkophores and siderophores separately, as a function of copper/iron amendment, and using community trajectory analysis. Singular findings are summarized as follows: 1) unlike lab-based studies, in our work we observe neither dramatic copper-modulation of iron demand, nor evidence of an iron-protective effect from copper toxicity. 2) The interplay between chalkophore/siderophore production supports a concept model wherein Microcystis spp. varies behavior to individually and uniquely manage copper/iron requirements in a phased manner. In being able to specifically screen for chalkophores, we observe a previously unreported link between chalkophore and microcystin production that may relate to iron-limitation. 3) Regarding harmful algal bloom (HAB) persistance, the lake water itself influences mesocosm changes; differentiated effects for iron regarding growth indicators and/or reduction of Fe-limitation stress were found at an HAB-free field station (Xukou Bay), likely a consequence of low bioavailability of iron in this station as compared to HAB-impacted stations (half the initial dissolved iron concentration, persisting throughout experiments). The low dissolved iron accompanies more intense chalkophore/siderophore community trajectories., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier Ltd.)

Environmental risk assessment (ERA) increasingly relies on speciation modeling of bioavailability. Heavy metals are the most prevalent pollutants globally, and dissolved organic matter (DOM) plays an important role in speciation and bioavailability of heavy metals. Due to the variation of DOM properties in natural aquatic systems, improvements to the standard one-size-fits-all approach to modeling metal-DOM interactions are needed for ERA. In this study, we investigate variations in DOM and lead (Pb)-DOM binding in Lake Tai (Taihu), a large, impacted lake in eastern China that is characterized by a complex drainage network and is an important water resource at a regional level, and we assess implications of our findings within the context of ERA needs. In our study, DOM in water samples collected from across the 2,400 km 2 area of Taihu was characterized using three-dimensional excitation-emission matrix and synchronous fluorescence spectroscopy spectra, the latter being used to calculate conditional stability constants for metal binding. Parallel factor analysis and peak picking were used to assess contributions of protein- and humic-like components of DOM, and fluorescence indices indicative of diagenetic processes were calculated. These quantities calculated from spectroscopic studies, in addition to water quality parameters, were analyzed by bivariate and multivariate analysis. Results show that different DOM components are highly variable across different regions of Taihu, and bivariate and multivariate analyses confirm that water quality and DOM characterization parameters are strongly interrelated. This reflects the different inputs, diagenetic and transport processes across the large expanse of Taihu. We find that the conditional stability constant of Pb-DOM binding is strongly affected by the water chemical properties and composition of DOM, though the conditional stability constant is not itself a parameter that differentiates lake water properties in different regions of the lake. The variability of DOM composition and Pb-DOM binding strength across Taihu is consistent with prior findings that a one-size-fits-all approach to metal-DOM binding may lead to inaccuracies in commonly used speciation models, and therefore such generalized approaches need improvement for regional-level ERA in complex watersheds. The approach taken here to obtain site-specific metal-DOM conditional stability constants for use in increasing the accuracy of speciation modeling is fit-for-purpose for ERA applications at regional levels because the approach is relatively simple, inexpensive, and amenable to high throughput analysis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Eutrophication or excessive nutrient richness is an impairment of many freshwater ecosystems and a prominent cause of harmful algal blooms. It is generally accepted that nitrogen and phosphorus nutrients are the primary causative factor, however, for systems subject to large anthropogenic perturbation, this may no longer be true, and the role of micronutrients is often overlooked. Here we report a study on Lake Tai (Taihu), a large, spatially diverse and hypereutrophic lake in China. We performed small-scale mesocosm nutrient limitation bioassays using boron, iron, cobalt, copper, molybdenum, nitrogen and phosphorus on phytoplankton communities sampled from different locations in Taihu to test the relative effects of micronutrients on in situ algal assemblages. In addition to commonly-used methods of chemical and biological analysis (including algal phytoplankton counting), we used flow cytometry coupled with data-driven analysis to monitor changes to algal assemblages. We found statistically significant effects of limitation or co-limitation for boron, cobalt, copper and iron. For copper at one location chlorophyll-a was over four times higher for amendment with copper, nitrogen and phosphorous than for the latter two alone. Since copper is often proposed as amendment for the environmental management of harmful algal blooms, this result is significant. We have three primary conclusions: first, the strong effects for Cu that we report here are mutually consistent across chlorophyll-a results, count data, and results determined from a data-driven approach to flow cytometry. Given that we cannot rule out a role for a Fe-Cu homeostatic link in causing these effects, future research into MNs and how they interact with N, P, and other MNs should be pursued to explore new interventions for effective management of HABs. Second, in view of the stimulatory effect that Cu exhibited, management of HABs with Cu as an algal biocide may not always be advisable. Third, our approach to flow cytometry offers data confirming our results from chemical and biological analysis, however also holds promise for future development as a high-throughput tool for use in understanding changes in algal assemblages. The results from this study concur with a small and emerging body of literature suggesting that the potential role of micronutrients in eutrophication requires further consideration in environmental management., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Aims: To evaluate a web-based educational smoking cessation programme on changes in the frequency of hospital-based nurses' self-reported interventions to help smokers quit using the 5 As (i.e. Ask, Advise, Assess, Assist, Arrange), to reduce exposure to second-hand smoke and to change attitudes about nurses' involvement in tobacco control., Background: Few nurses in China support smokers' quit attempts using evidence-based smoking cessation interventions based on the 5 As. Limited knowledge is a barrier to intervention. Web-based tobacco cessation programs have the potential to reach a large population of nurses., Design: A prospective single-group design with pre-, 3- and 6-month follow-up after the educational programme evaluated the feasibility of conducting web-based educational programs in two cities in China in 2012-2013., Methods: Frequency of interventions was assessed using a valid and reliable web-based survey with a convenience sample of nurses from eight hospitals in Beijing and Hefei, China. Generalized linear models, adjusting for age, clinical setting, education and site were used to determine changes in the consistent (usually/always) use of the 5 As from baseline to 3 and to 6 months., Results: Nurses (N = 1386) had baseline and/or 3- and 6-month data. At 6 months, nurses were significantly more likely to Assess, Assist and Arrange for smoking cessation and recommend smoke-free home environments. There was significant improvement in attitudes about tobacco control., Conclusions: Nurses receiving web-based smoking cessation education significantly increased self-reports of frequency of providing interventions to patients who smoke, including recommending smoke-free home environments to support quit attempts., (© 2015 John Wiley & Sons Ltd.)