The SSC cycle: a PDCA approach to address site-specific characteristics in a continuous shallow water quality monitoring project

In any water quality-monitoring project there are several critical success factors that must be adequately addressed in order to ensure the implementation and realization of the monitoring objectives. Site selection is one of these critical success factors. The monitoring sites must be selected to comply with the monitoring and data quality objectives. In the real world, ideal monitoring setting conditions are difficult to achieve, and compromises must be made in order to locate the monitoring stations that best represent the environment to be monitored. Site-specific characteristics are all the environmental, logistical and management factors particular to the monitoring site, that could influence the fulfilment of the monitoring and data quality objectives. Therefore, during the site selection process, it is essential to properly consider and evaluate these site-specific characteristics. The SSC cycle was developed with this goal in mind, to assist the monitoring team to systematically address site-specific characteristics. The cycle is a methodology to organize the site-specific characteristics in different categories, and to ensure a comprehensive overview of these characteristics throughout the project life cycle.     

Mercury fractionation in stream sediments from the Quadrilátero Ferrífero gold mining region, Minas Gerais State, Brazil

The Iron Quadrangle (IQ) region, located in the state of Minas Gerais, has been the most important gold producing area in Brazil since the end of seventeenth century. The use of mercury for gold amalgamation in small scale mines has been responsible for large release of Hg to aquatic and terrestrial environments during 300 years of mining. The present work sought to evaluate the fractionation of Hg in stream sediments is the southern region of the IQ by utilizing sequential extraction. Since mobility and availability of Hg are related to its distribution among sediment partitions, fractionation methods provide detailed information on the ecotoxicological impact and risks associated to the presence of Hg in sediments. The total Hg concentration varied from 179.3 to 690.1 microg kg( - 1) and Hg(0) accounted for the majority at all sample sites, ranging from 42% to 56% of the total.     

Carbon monoxide and carbon dioxide concentrations in Santiago de Chile associated with traffic emissions

CO/CO₂ ratios have been measured in different locations of Santiago de Chile city. Measurements were carried out in a tunnel (prevailing emissions from cars with catalytic converter) and close to heavy traffic streets. Concentrations measured along the city traffic tunnel or temporal profiles of concentrations measured near heavy traffic streets allow an estimation of CO/CO₂ ratios emitted from mobile sources. Values obtained range from 0.0045 ± 0.0006 to 0.0100 ± 0.0004 and depend on the prevailing type of mobile sources. In particular, lowest values were found close to a street with heavy traffic dominated by diesel-powered public transportation, while the highest values were found at the city tunnel. Places located near streets of mixed mobile sources (public buses and cars) showed intermediate values. Average CO/CO₂ ratios are compatible with emission factors proposed for Santiago’s main mobile sources.     

The relationship between blood alcohol concentration (BAC), age, and crash risk

PROBLEM: The role of age (youth and driving inexperience) and alcohol as major risk factors in traffic crash causation has been firmly established by numerous studies over the past 50 years. Less well established is how the two variables interrelate to influence crash risk. Some investigations have hypothesized an interactive or synergistic effect in which young drivers with less experience and a greater tendency to take risks are more adversely affected at lower blood alcohol concentrations (BACs) than are older drivers. The evidence for this hypothesis is mixed. Resolution of this issue has important implication for developing countermeasures directed at the young driver crash problem. METHOD: Case control data previously collected in Long Beach and Fort Lauderdale were reanalyzed using a more sensitive method for detecting interaction effects than used in the original analysis. A conditional logistic regression analyses found a highly significant agexBAC interaction (P<.0001) involving differences between drivers under 21 and those 21 and older. DISCUSSION: The results clearly indicate that positive BACs in drivers under 21 are associated with higher relative crash risks than would be predicted from the additive effect of BAC and age. It is likely that two mechanisms are operating to cause the interaction. First, it seems likely that the crash avoidance skill of young novice drivers would be more adversely affected by alcohol due to their driving inexperience, immaturity, and less experience with alcohol. Second, drivers under 21 who choose to drink and to drive after drinking probably have pre-existing characteristics that predisposed them to risk taking and crash involvement apart from any increased vulnerability to alcohol impairment. IMPACT ON INDUSTRY: The results support increased enforcement of zero-tolerance BAC laws for minors.     

Water quality assessment, by statistical analysis, on rural and urban areas of Chocancharava River (Río Cuarto), Córdoba, Argentina

Water quality has degraded dramatically in the Chocancharava River (Río Cuarto, Córdoba, Argentina) due to point and non-point sources. This paper aims to assess spatial and temporal variations of physical and chemical parameters of the river. Six sampling sites and six sampling campaigns were developed. During the period 2007–2008, wet and dry seasons were included. A statistical analysis was carried out with 23 physical and chemical variables. Then, a new statistical analysis was carried out including the Riparian Corridors Quality Index and the physical and chemical variables (24 variables). Considering a multivariate system, analysis of variance, principal component analysis and cluster analysis were used. From the statistical analysis, the river was divided into two zones with different degrees of contamination. The most polluted zone is due to pollution inputs of urban, industrial and agricultural sources. This area showed a remarkable deterioration in water quality, mainly due to wastewater discharges. According to Riparian Quality, better results were found in sections of poor water quality, due to the fact that the river bank forest was less degraded downstream of the sewage discharge.     

Spatial and seasonal distribution of 17 endocrine disruptor compounds in an urban estuary (Mondego River,Portugal): evaluation of the estrogenic load of the area

The Mondego River estuary demonstrates signs of pollution, but the levels of endocrine disrupting compounds (EDCs), such as the natural (17β-estradiol and estrone) and pharmaceutical (17α-ethynylestradiol) estrogens, xenoestrogenic industrial pollutants (4-octylphenol, 4-nonylphenol, and their mono- and diethoxylates and bisphenol A), phytoestrogens (formononetin, biochanin A, daidzein, and genistein), and sitosterol were either poorly or never measured in this area. Thus, to conclude about the influx of EDCs in this estuary, water samples were taken every 2 months, during 1 year (2010) in low tide, at eight sites distributed along the estuary. Water samples (1 L) were preconcentrated in the Oasis HLB cartridges and cleaned in silica cartridges before their analysis by GC-MS. In summer, potentially hazardous amounts of estrogens (≈26 ng L^?1), alkylphenols (≈11.5 μg L^?1), alkylphenolethoxylates (≈13 μg L^?1), and phytoestrogens (≈5.6 μg L^?1) were measured. These data suggest that changes in the hydrodynamics of the estuary coupled with the increase of water temperatures interfere with the amount of EDCs in the water. Complementary physicochemical parameters also point to high levels of anthropogenic pollution in this area. Globally, the estrogenic load, expressed in ethynylestradiol equivalents, attained 71.8 ng L^?1 demonstrating that, all together, the measured EDCs pose important health risks for both biota and humans.     

Are Roadkill Hotspots in the Cerrado Equal Among Groups of Vertebrates?

Environmental Management - Understand the spatial distribution of wildlife roadkill is necessary to design mitigation measures minimizing damage to the fauna and the human population. Thus, we...     

Algae turf scrubber and vertical constructed wetlands combined system for decentralized secondary wastewater treatment

Environmental Science and Pollution Research - Water shortage is a current problem faced by many regions. The deterioration of water bodies driven by the directly discard of untreated wastewater...