Heavy metal pollution and health risk assessment in the Wei River in China.

From data collected monthly at 26 monitoring cross sections in the Wei River in the Shaanxi Region of China during the period 2008-2012, the temporal pollution characteristics of heavy metals (Hg, Cd, Cr(VI), Pb, and As) were analyzed based on a heavy metal pollution index (HPI). The monthly HPI values of the five heavy metals in the river fluctuated greatly in 2008 and then declined gradually with time. This general trend of reduction in HPI appears not to have a seasonal variation and most likely resulted from the continued improvement in heavy metal pollution control strategies implemented by local environmental agencies combined with a significant improvement in wastewater treatment capacities. Among the five heavy metals, Cd and Pb were below 0.1 and 3 µg L(-1), respectively, at all the sampling points in the studied areas in the year 2012. The detection rates of As, Hg, and Cr(VI) were in the order of Hg > Cr(VI) > As. Hg, Cr(VI), and As exceeded, in a month of the dry season in 2012, the standard limits for category III surface waters according to the China Environment Quality Standards for Surface Water (CEQSSW). Based on the assessment using the HPI method, the pollution status of these heavy metals in water of the Wei River in the Shaanxi Region was generally at an acceptable level, but exhibited distinctive characteristics between the main stream river and tributaries. Most of the tributaries were more seriously polluted than the main river. A health risk assessment was conducted based on the Human Health Risk Assessment (HHRA) method recommended by the United States Environmental Protection Agency (USEPA). Apart from As, the health risk for the five heavy metals in the region were at acceptable levels for drinking water sources (hazard quotient (HQ) < 1, carcinogenic risk (CR) ranged from 10(-4)-10(-6)) according to the Risk Assessment Guidance for Superfund (RAGS), USEPA. Arsenic was identified as the most important pollutant of concern among the five heavy metals; both its values of the HQ and CR indicated potentially adverse health risks for the local population.

[History and present status of butterfly monitoring in Europe and related development strategies for China].

Butterfly is an important bio-indicator for biodiversity monitoring and ecological environment assessment. In Europe, the species composition, population dynamics, and distribution pattern of butterfly have been monitored for decades, and many long-term monitoring schemes with international effects have been implemented. These schemes are aimed to assess the regional and national variation trends of butterfly species abundance, and to analyze the relationships of this species abundance with habitat, climate change, and other environmental factors, providing basic data for researching, protecting, and utilizing butterfly resources and predicting environmental changes, and playing important roles in the division of butterfly' s threatened level, the formulation of related protection measures, and the protection and management of ecological environment. This paper reviewed the history and present status of butterfly monitoring in Europe, with the focus on the well-known long-term monitoring programs, e. g. , the UK Butterfly Monitoring Scheme and the Germany and European Union Butterfly Monitoring Scheme. Some specific proposals for conducting butterflies monitoring in China were suggested.