Health hazard prospecting by modeling wind transfer of metal-bearing dust from mining waste dumps: application to Jebel Ressas Pb–Zn–Cd abandoned mining site (Tunisia)

This work presents a modeling approach to simulate spatial distribution of metal contamination in aerosols with evaluation of health hazard. This approach offers the advantage to be non-intrusive, less expensive than sampling and laboratory analyses. It was applied to assess the impact of metal-bearing dust from mining wastes on air quality for a nearby community and agricultural lands in Jebel Ressas (Tunisia) locality. Dust emission rates were calculated using existing parameterization adapted to the contamination source composed of mining wastes. Metal concentrations were predicted using a Gaussian model (fugitive dust model) with, as input: emission rates, dump physical parameters and meteorological data measured in situ for 30 days in summertime. Metal concentration maps were built from calculated PM10 particle concentrations. They evidence the areas where Pb and Cd concentrations exceeded WHO guidelines (0.5 and 0.005 µg/m³, respectively). Maximum concentrations of Pb and Cd in PM10 are, respectively, of 5.74 and 0.0768 µg/m³ for measured wind speed values up to 22 m/s. Preferential areas of contamination were determined in agricultural lands to the NW from the source dump where Pb and Cd exceeded guidelines up to a distance of 1,200 m. The secondary spreading directions were SW and E, toward the village. Health hazard prospecting shown that a major part of the village was exposed to contaminated dust and that daily hazard quotient (HQ) values reached locally 118 and 158, respectively, for Pb and Cd during the study period. However, HQ variations in the village are high, both temporally and geographically.     

多壁碳纳米管存在环境下Pb、Zn对斑马鱼毒性的变化(The Change of the Toxicity of Pb and Zn on Zebrafish in the Case of the Existence of Multi-Walled Carbon Nanotubes)

研究了重金属铅、锌对斑马鱼的急性毒性效应及在人工碳纳米材料——多壁碳纳米管存在环境下,铅、锌对斑马鱼毒性的变化.结果显示,随着铅(Pb(NO3)2)、锌(ZnSO4)浓度的增加以及染毒时间的延长,斑马鱼死亡率逐渐增加;单一多壁碳纳米管悬液(10mg·L-1)对斑马鱼无明显毒性效应.Pb和Zn对斑马鱼24h、48h和96h的LC50分别为5.38mg·L-1、3.99mg·L-1、3.83mg·L-1和26.37mg·L-1、21.39mg·L-1、20.62mg·L-1;在多壁碳纳米管存在条件下,二者对斑马鱼24h、48h和96h的LC50分别为2.74mg·L-1、2.26mg·L-1、2.15mg·L-1和21.85mg·L-1、17.17mg·L-1、16.77mg·L-1.多壁碳纳米管存在条件下铅、锌对斑马鱼的LC50显著降低,提示碳纳米材料可能会增加重金属对水生生物的毒性.     

Major and trace elements in paddy soil contaminated by Pb–Zn mining: a case study of Kočani Field,Macedonia

The objective of this study was to assess the bulk chemical composition as well as the extent and severity of heavy metal contamination in the paddy soil of Kočani Field (eastern Macedonia). The results revealed that the paddy soil of the western part of Kočani Field is severely contaminated with Pb, Zn, As and Cd in the vicinity of the Zletovska River due to irrigation with riverine water that is severely affected by acid mine and tailing effluents from the Pb–Zn mine in Zletovo. The detected total concentrations of these metals are far above the threshold values considered to be phytotoxically excessive for surface soil. The paddy soil in the vicinity of the Zletovska River was also found to exhibit elevated levels of Ba, Th, U, V, W, Mo, Cu, Sb, Bi, Ag, Au, Hg and Tl, with concentrations above their generally accepted median concentration values obtained during this study. A correlation matrix revealed that the Mn and Fe oxides/hydroxides are the most important carrier phase for several trace elements, with the exception of rare earth elements (REEs). These also represent a major sink for the observed heavy metal pollution of the soil. REEs are mostly associated with two phases: light (L)REEs are bound to K-Al, while heavy (H)REEs are bound to Mg-bearing minerals. Although there is no direct evidence of a health risk, the paddy soil in the vicinity of Zletovska River needs further investigation and an assessment should be made of its suitability for agricultural use, particularly in view of the highly elevated concentrations of Pb, Zn, As and Cd.     

An assessment of air pollution episodes in the urban area of athensfor the period 1984–1994

Air pollution episodes in the greater Athens area for the period 1984–1994 were examined to assess the type, frequency and repetitivity of air pollution in the examined area. The assessment depends strongly on the definition of an air pollution episode (APE), namely if it is the narrow or broad one. Results from the statistical analysis of the data record‐on the basis of the broad definition of the APE‐show a declining trend in the number of APEs especially for non‐photochemical species, a sharp increase of APEs from 1987 to 1993 due to high ozone levels and a similarly sharp decrease thereafter, and a decreasing trend of nitrogen dioxide episodes from the year 1992 thereon. Interannual examination of APEs shows that they occur in higher numbers during the period November to January and in the period May to July. Finally an examination of the number of days for which urgent‐short term‐measures were taken to reduce high levels of atmospheric pollution, shows a decreasing trend from 1989, with the exception of 1994 where the sharp increase in the number of days is due to the application of the urgent measures at a precautionary mode, i.e. when pollution loads exceed the alert levels, air pollution increases in rapid rates and meteorological conditions are supportive for an enhanced APE.     

Mercury accumulation in soils and plants in the Almadén mining district, Spain: one of the most contaminated sites on Earth

Although mercury (Hg) mining in the Almadén district ceased in May 2002, the consequences of 2000 years of mining in the district has resulted in the dissemination of Hg into the surrounding environment where it poses an evident risk to biota and human health. This risk needs to be properly evaluated. The uptake of Hg has been found to be plant-specific. To establish the different manners in which plants absorb Hg, we carried out a survey of Hg levels in the soils and plants in the most representative habitats of this Mediterranean area and found that the Hg concentrations varied greatly and were dependent on the sample being tested (0.13–2,695 μg g⁻¹ Hg). For example, the root samples had concentrations ranging from 0.06 (Oenanthe crocata, Rumex induratus) to 1095 (Polypogon monspeliensis) μg g⁻¹ Hg, while in the leaf samples, the range was from 0.16 (Cyperus longus) to 1278 (Polypogon monspeliensis) μg g⁻¹ Hg. There are four well-differentiated patterns of Hg uptake: (1) the rate of uptake is constant, independent of Hg concentration in the soil (e.g., Pistacia lentiscus, Quercus rotundifolia); (2) after an initial linear relationship between uptake and soil concentration, no further increase in Hg_plant is observed (e.g., Asparagus acutifolius, Cistus ladanifer); (3) no increase in uptake is recorded until a threshold is surpassed, and thereafter a linear relationship between Hg_plant and Hg_soil is established (e.g., Rumex bucephalophorus, Cistus crispus); (4) there is no relationship between Hg_plant and Hg_soil (e.g., Oenanthe crocata and Cistus monspeliensis). Overall, the Hg concentrations found in plants from the Almadén district clearly reflect the importance of contamination processes throughout the study region.     

The effects of developmental lead (Pb) exposure on the expression of the CTGF and TGF-β1 in hippocampus of pups

Pregnant mice were exposed to control (0%), low (0.1%), moderate (0.5%), and high (1%) lead (Pb) acetate in deionized drinking water from the first day of gestation to postnatal day (PND) 21. Pb concentration was determined in blood and the hippocampus at the 7th, 14th, or 21st day of neonatal mice pups. The expression of connective tissue growth factor (CTGF) and TGF-β1 mRNA and protein was also measured in the hippocampus using RT-PCR and immunohistochemistry assays. The expression of CTGF and TGF-β1 mRNA was up-regulated in hippocampus in Pb-exposed groups. These results were further confirmed by immunohistochemistry staining. Data suggest that CTGF and TGF-β1 genes are differentially regulated and are affected by Pb.     

The impact of unconfined mine tailings and anthropogenic pollution on a semi-arid environment – an initial study of the Rodalquilar mining district, south east Spain

A geochemical study of stream sediments near Rodalquilar (South-east Spain) was undertaken to investigate the impact of processing activities associated with nearby gold mining. Despite the semi-arid nature of the area, visual inspection of tailings indicates that considerable fluvial erosion occurs during rainfall events. Geochemical analysis demonstrates that Mo, Sb, Te, Bi and As are all found at elevated levels in stream sediments downstream of the tailings site. Elevated levels of Pb, Cu and Zn were also noted in stream sediments. Statistical analysis demonstrates that four factors control trace-element distribution. Factor 1 displays a strong association of Mo, Sb, Te and Bi and As and is attributed to the mine tailings. Factor 2 displays an association of Pb and Cu, and is most easily attributed to anthropogenic pollution. Factor 3 distinguishes Au and reflects the selective nature of ore-processing methods employed at the site. Factor 4 only highlights Zn, reflecting that it is derived from several, probably unrelated, sources.     

Diel migration of phytoplankton and spectral light field in the Ría de Vigo (NW Spain)

Diel migration of Mesodinium rubrum, Eutreptiella sp., Scrippsiella trochoidea, Dinophysis acuminata and Ceratium furca throughout a 24 h cycle is described for a stable, well-stratified estuary (Ría de Vigo, NW Spain). Daily changes in light quantity and in spectral light ratios i.e. red:far-red, blue:red, green:red and blue:green have been analysed. The spectral light ratios changed at twilight and around noon at various depths. Some of the downward migrations were well predicted by Stokes' law, while other migrations were faster and deeper than calculated. The coincidence of these movements with abrupt changes in red:far-red, green:red and blue:green light ratios is discussed. Some species are able to migrate through the pycnocline, whereas others do not seem to be able to do so. Several species are present in maximum numbers at depth at night, while others display upward migration independent of light, suggesting the existence of endogenous rhythms. Upward migration at dusk began with dispersal of populations, with renewed aggregation at the sea surface coincident with an increase in the red:far-red ratio at 6 m and the green:red ratio at 6 and 10 m. Based on direct evidence for the control of flagellar mobility by light quality reported by other authors from laboratory studies, it is suggested that, together with other cues, spectral light ratios of different light qualities modulate vertical phytoplanktonic migration. Received: 18 July 1997 / Accepted: 17 October 1997     

Assessing and simulating the major pathway and hydrogeochemical transport of arsenic in the Beitou–Guandu area,Taiwan

This study involved assessing and simulating the probable major pathways (surface and subsurface flow) and hydrogeochemical transport of arsenic (As) in the Beitou–Guandu area, Taiwan. A one-dimensional (1-D) generic, reactive, chemical transport model (PHREEQC) was adopted. The calibrated model showed that As transported to the downstream Guandu plain and Tan Shui river mouth accounted for 50.7 and approximately 100 % of the As in the subsurface flow pathway, respectively, suggesting that subsurface flow constituted a major As pathway. The highest As water concentration occurred near the Beitou geothermal valley because of the low pH and high redox potential in both the surface and subsurface pathways. However, As may be scavenged by aqueous Fe(II) in a reducing environment. The As concentrations in the downstream Guandu plain and Guandu wetland decreased as the simulated time increased, resulting in the adsorption of As on the surface of Fe oxydroxides and limiting the mobility of As in the surface flow pathway. The major retardation mechanism of As mobility in the subsurface flow pathway of the Guandu plain and Guandu wetland was governed by the adsorption reactions of iron-oxide and iron-sulfide minerals. The 1-D transport model was applied to predict the evolution of As in the subsurface flow pathway from 2013 to 2020. The results indicated that the As concentrations in all cells gradually increased. The geochemical redox reactions of As in the subsurface pathway subsequently led to the oxidization of As-bearing sulfides, causing As concentrations to rise substantially in the hillside area.

     

Characterization of chemical species in universal sampler (PM2.5 and PM2.5–10) aerosols in suburban area of central Taiwan

Aerosol samples of particulate and chemical species for PM₁₀ (particulate matter with aerodynamic diameters less than 10 μm) collected by Universal sampler were studied from June to August 1998 in the suburban area of central Taiwan. The ratios of PM_2.5/PM_2.5–10 displayed that the fine particles (particle size < 2.5 μm) are prevailing in the suburban site. Ion Chromatography was used to analyze for the water‐soluble ions: sulphate and nitrate in the Universal samples. Also, the collected samples were analyzed by atomic absorption spectrophotometry for the elemental analysis of Ca, Fe, Pb, Cu and Cr. The results indicated that the crustal elements (Ca and Fe) and resuspended matters were dominated in the coarse particulate mode while the anthropogenic elements (Cr, Pb, Cu) and sulphate components are mainly in the fine particle fraction. The results also showed that the sulphate and nitrate make the largest portion of the chemical species collected by Universal sampler (PMio). The concentrations of heavy metals in THU are generally high, owing to the higher motor vehicle and industrial density nearby. The degree of pollution from this source differs from day to day, depending on the motor vehicle density.     

Trends over 1999–2014 in the concentrations of Ba,Cs, Co,Mo, Pb,Sb, Tl,and W in urine of US children aged 6–11 years

Data from National Health and Nutrition Examination Survey for children aged 6–11 years for 1999–2014 were used to study time trends and factors affecting the urinary levels of barium, cobalt, cesium, molybdenum, lead, antimony, thallium, and tungsten. Adjusted levels in urine declined every two years by 5.9% for barium, by 1.2% for cesium, by 18.2% for lead, and by 14% for antimony. For every additional smoker smoking inside a home, the levels of barium increased by 10.6% and for lead by 10%, but for tungsten levels decreased by 7.7%.     

Cadmium (Cd) and zinc (Zn) accumulation by Thai rice varieties and health risk assessment in a Cd–Zn co-contaminated paddy field: Effect of soil amendments

Environmental Geochemistry and Health - Zinc mining and smelting activities result in cadmium (Cd) and zinc (Zn) contamination in rice grains, causing deleterious impacts on human health and local...     

Rapid synthesis of mono/bimetallic (Zn/Co/Zn–Co) zeolitic imidazolate frameworks at room temperature and evolution of their CO2 uptake capacity

Environmental Chemistry Letters - Carbon dioxide (CO2) emissions from fossil fuels cause air pollution and lead to adverse impact on environment. To achieve low-carbon economy, capturing CO2 in the...     

A coupled numerical model to investigate the air–sea interaction at the coastal upwelling area of Cabo Frio,Brazil

This work investigates the capability of an oceanic numerical model dynamic and thermodynamically coupled to a three-dimensional mesoscale atmospheric numerical model to simulate the basic features of the air–sea interaction in the coastal upwelling area of Cabo Frio (RJ, Brazil). The upwelling/downwelling regime is an important feature in the oceanic circulation of Cabo Frio and determines the sustainability of local ecosystems. This regime is predominantly driven by the atmospheric circulation and is well documented, being suitable to be used as test reference for atmospheric and oceanic coupled and uncoupled models. The oceanic boundary conditions, coastline shape and coupling effect have been tested. The uncoupled oceanic model forced by a NE (SW) wind field generates a realistic upwelling (downwelling) phenomenon regardless of the proximity of the lateral boundary and how realistic is the shape of the coastline. The atmospheric-oceanic coupled model generates an upwelling location and intensity similar to the uncoupled simulation, but the upwelling is gradually enhanced by the sea-breeze circulation. It also generates vertical profiles of mixing ratio that compare better to the observations than the uncoupled simulation and air potential temperature and wind vertical profiles that represent particular features of the atmospheric circulation at Cabo Frio.     

Determination of the framework conditions and research–development needs for the dissemination of cleaner (sustainable) production applications in Turkey

SUMMARY

A cross-section survey of five states in Nigeria was derived through a stratified random sampling technique in 1999–2000 to assess the contribution of traditional knowledge in environmental conservation. Data were collected through a combination of questionnaire survey and discussions with stakeholders, with field assessment of herb gardens. Interviews were held with 1953 respondents composed of women, men and youths drawn from 20 settlements in 10 local government areas in the savanna and rainforest ecological zones.

The results derived from data analysis indicated that: (i) the rural communities were willing to accept integrated rural land-use practices that would conserve species and habitats, sustain the rural economy and the socio-cultural lifestyles of the people; (ii) the people at the local level had some basic knowledge about species and habitats, and have been conserving the forests with traditional land tenure rights; and (iii) environmental projects acceptable to the rural communities must be beneficial to the people, participatory, integrated with traditional knowledge and based on local needs.     

Dynamics of grass–clover mixtures—An analysis of the response to management with the PROductive GRASsland Simulator (PROGRASS)

A dynamic plot-scale model PROGRASS was developed to simulate the seasonal and inter-annual dynamics of productive, cut grass/clover mixtures in response to management, and specifically to examine the role of root development on grass/clover interactions. The model was parameterized by virtue of data for dry matter yield, leaf area index, root mass, soil mineral N uptake and biological N fixation from a long-term field trial in north-eastern Switzerland. It was tested using 5 years of independent data for yield and clover fraction from a field experiment with two management regimes carried out on the Swiss Central Plateau. The results of transient simulations indicated that under intensive fertilization grass dominance was initiated by preferential allocation of assimilates to the roots. The rapid growth of the grass root system lowered the substrate C:N ratio, favouring carbon allocation to the shoot, which eventually provided competitive advantages with respect to light interception. Under extensive management, limited N acquisition capacity of the grass root system maintained preferential allocation to the roots, limiting shoot development in the grass and leading to clover dominance. Co-existence regimes with dominance by one of the components were also found in equilibrium experiments, with a transition regime from clover to grass dominance for annual N applications in the range 100–200 kg N ha⁻¹ y⁻¹ that reflected adjustments of the root system to fertilization. It is concluded that the dynamics of grass/clover mixtures is driven by negative and positive feedbacks in the soil–plant system that are strongly controlled by root development and therefore by the allocation patterns of the grass component.     

Influence of large-spectrum environmental contamination on the micro–meiobenthic assemblages in harbour sediments of the ligurian sea (W Mediterranean)

The concentration of a large spectrum of environmental contaminants (PCBs, PAHs, pesticides and metals) was assessed in surface sediments of two Ligurian harbours (Sanremo and Alassio, NW Mediterranean Sea, Italy) and their relative impact on micro–meiobenthic assemblages was analysed. Concentration, distribution and relative importance of the different contaminants varied considerably between harbours in relation to the different anthropic activities and contamination sources. Results from Principal Component Analysis indicated that high levels of contaminants were typically correlated with low micro–meiobenthic abundance in the sediment. Heavy metals and the organic enrichment were the main factors affecting the distribution and abundance of the bacterial and meiofaunal assemblages in Alassio harbour, whereas hydrocarbons and pesticides played a major role in Sanremo sediments. Neither the bacteria density nor the meiofauna abundance were dependent on sediment grain size, suggesting that micro–meiobenthic parameters may be under the influence of other variables. Our results suggest that high concentrations of contaminants independently from their source or typology are responsible for the impact observed on micro–meiobenthic assemblages in these harbours.     

Trace elements in commercial marine organisms from the Russian part of the Northwest Pacific (2010–2018)

Environmental Chemistry Letters - We report levels of trace elements in commercially harvested species from the Far Eastern seas of Russia from 2010 to 2018. The best studied organisms in this...     

Levels and distributions of organochlorine pesticides in the soil–groundwater system of vegetable planting area in Tianjin City,Northern China

To study the influence of long-term pesticide application on the distribution of organochlorine pesticides (OCPs) in the soil–groundwater system, 19 soil samples and 19 groundwater samples were collected from agricultural area with long-term pesticide application history in Northern China. Results showed that the composition of OCPs changed significantly from soil to groundwater. For example, ∑DDT, ∑HCH, and ∑heptachlor had high levels in the soil and low levels in the groundwater; in contrast, endrin had low level in the soil and high level in the groundwater. Further study showed that OCP distribution in the soil was significantly influenced by its residue time, soil organic carbon level, and small soil particle contents (i.d. <0.0002 mm). Correlation analysis also indicates that the distribution of OCPs in the groundwater was closely related to the levels of OCPs in the soil layer, which may act as a pollution source.