A regulatory perspective on the radiological impact of NORM industries: the case of the Spanish phosphate industry

Radioactive and chemical risks coexist in NORM industries although they are usually addressed separately by regulations. The European Union (EU) has developed extensive legislation concerning both matters, which has been diversely reflected in national policies. We consider the case of the Spanish phosphate industry and analyse to which extent regulatory mandates have reduced the historical and ongoing radiological impact on the environment of phosphate facilities. Although no specific radiological constraints on effluent monitoring and release or on waste disposal have yet been imposed on NORM industries in Spain, other environmental regulations have achieved a substantial reduction on the phosphate industry impact. Nevertheless, a more efficient control could be established by eliminating the current conceptual and practical separation of chemical and radioactive risks in NORM industries. We highlight research needs to accomplish so and propose shorter-term measures that require active cooperation among the regulatory bodies involved.     

Critical loads for Finnish lakes: comparison of three steady-state models

Three simple steady-state water-chemistry models are used to calculate critical loads of sulfur for lakes in Finland. Because of the high concentrations of organic matter in Finnish lakes, the influence of organic anions on the calculation of critical loads has been given special attention. The first two methods are well known ion-balance methods which have been used in many previous lake-acidification studies. The third method, developed for this study, includes the numerical solution of equilibrium equations for organic anions, inorganic carbon species and inorganic monomeric aluminum. The original pH and aluminum concentration of the lakes are estimated with this model, and a method to estimate the original acid neutralizing capacity (ANC) by simulating a Gran-titration is also tested on the lake data. Uncertainty in the predictions is estimated by varying the most critical model parameters.     

Variation in sex steroids and phallus size in juvenile American alligators (Alligator mississippiensis) collected from 3 sites within the Kissimmee-Everglades drainage in Florida (USA)

This 3-year study was designed to examine variation in plasma sex steroids, phallus size, and the standard error (S.E.) associated with these endpoints in juvenile alligators collected from 3 sites within the Kissimmee-Everglades drainage (Florida, USA) with varying concentrations of sediment organochlorine contaminants. We hypothesized that decreased plasma sex steroid concentrations and phallus size would be observed in the higher contaminant site when compared to the intermediate and lower contaminant sites. Furthermore, we hypothesized that greater S.E. associated with these endpoints would be observed for the populations from more contaminated sites. We found that differences existed with females from the higher contaminant site exhibiting lower plasma estradiol-17beta (E2) and testosterone (T) concentrations. Males from the higher contaminant site exhibited smaller phallus sizes than males from the intermediate and lower contaminant sites. Smaller phallus size in this case differed from that reported in Lake Apopka male alligators [Gen. Comp. Endocrinol. 116 (1999) 356] in that a significant positive relationship between body size and phallus size existed. No difference among sites was observed in plasma T for males. Lower S.E. was associated with E2 and T concentrations in females from the higher contaminant site and in phallus size in males from the higher contaminant site. This pattern was opposite to what we had hypothesized. We concluded that variation in plasma E2 and T concentrations, phallus size, and the S.E. associated with these endpoints exists among the 3 sites with the patterns matching the patterns of organochlorine contamination, although S.E. patterns were opposite to what was predicted.     

Manganese uptake and accumulation by the hyperaccumulator plant Phytolacca acinosa Roxb. (Phytolaccaceae)

The perennial herb Phytolacca acinosa Roxb. (Phytolaccaceae), which occurs in Southern China, has been found to be a new manganese hyperaccumulator by means of field surveys on Mn-rich soils and by glasshouse experiments. This species not only has remarkable tolerance to Mn but also has extraordinary uptake and accumulation capacity for this element. The maximum Mn concentration in the leaf dry matter was 19,300 microg/g on Xiangtan Mn tailings wastelands, with a mean of 14,480 microg/g. Under nutrient solution culture conditions, P. acinosa could grow normally with Mn supplied at a concentration of 8000 micromol/l, although with less biomass than in control samples supplied with Mn at 5 micromol/l. Manganese concentration in the shoots increased with increasing external Mn levels, but the total mass of Mn accumulated in the shoots first increased and then decreased. At an Mn concentration of 5000 micromol/l in the culture solution, the Mn accumulation in the shoot dry matter was highest (258 mg/plant). However, the Mn concentration in the leaves reached its highest value (36,380 microg/g) at an Mn supply level of 12,000 micromol/l. These results confirm that P. acinosa is an Mn hyperaccumulator which grows rapidly, has substantial biomass, wide distribution and a broad ecological amplitude. This species provides a new plant resource for exploring the mechanism of Mn hyperaccumulation, and has potential for use in the phytoremediation of Mn-contaminated soils.     

Modeling of agricultural drought risk pattern using Markov chain and GIS in the western part of Bangladesh

The aim of the study is to assess the agricultural drought risk condition in the context of global climate change in the western part of Bangladesh that covers about 45% area of the country for the period of 1960–2011. Drought Index (DI) and Drought Hazard Index (DHI) have been calculated by Markov Chain analysis and that of Drought Vulnerability Index (DVI) from socioeconomic and physical indicators. The DI values show that the northern part in general is more drought-prone, having less crops prospect, whereas the southern part is less drought-prone with high crop potentiality. The probability of extreme drought occurrence increases in recent decades in some parts as a result the drought events become more frequent in the areas. The DHI ranges from 15 to 32, and northern part suffers from more extreme drought hazards than that of southern part. DVI also indicates that northern part is exposed to high to very high drought vulnerability as higher percentage of illiterate people are involved in agricultural practices and high percentage of irrigation to cultivable land, but southern part exposed to moderate to low vulnerability because of low values of vulnerability indicators. Finally, agricultural drought exists at high risk condition in northern part and low in southern parts and 21.63, 26.54 and 29.68% of the area poses very high, high and moderate risk, respectively. So, immediate adaptation measures are needed keeping in mind climate features like rainfall and temperature variability, drought risk and risk ranking to make viable adaptation measures.     

Effect of low-molecular weight organic acids on phosphorus release and phytoavailabilty of phosphorus in phosphate rocks added to soils

Phosphorus (P) is critically needed to improve soil fertility in many parts of the world. The use of water-soluble P fertilizers, e.g., single super-phosphate and triple super-phosphate in developing countries to improve crop production has been limited primarily by their high cost. The presence of indigenous phosphate deposits in some countries provides an incentive for direct application or local chemical treatment at low cost to improve the solubility of low reactive phosphate rocks (PRs). The use of naturally occurring low-molecular weight organic acids (LMWOAs) that are produced in soil as microbial metabolites or plant exudates from dead or living cells represents a new perspective in PR research. The LMWOAs contain various functional groups that may play a significant role in PR dissolution. Little information is available, however, about the potential of LMWOAs in releasing P from PRs. This study reports P release from 12 PRs, four each of low, medium, and high reactivity, obtained from various deposits (Kodjari, Tahoua, North Carolina, Gafsa, Khouribga, Tilemsi Valley, Central Florida, Sechura, Minjingu, North Florida, Hahotoe, and Parc W) using nine LMWOAs containing mono-, di-, and tri-carboxylic groups and a mineral acid (H₂SO₄). Laboratory studies showed that the organic acids are effective in releasing P from low and medium reactive PRs, but very ineffective in releasing P from high reactive PRs. The average amounts of P released by all the organic acids from the three types of PRs were 65.5 mmol kg⁻¹ PR from the low reactive PRs, 55.1 mmol kg⁻¹ from the medium, and 11.1 mmol kg⁻¹ from the high; those released from across all the PRs were 21.9 by the mono-carboxylic acid group, 54.2 by the di-carboxylic acid group, and 57.0 mmol P kg⁻¹ by the tri-carboxylic acid group. The P released was negatively correlated with the equilibrium pH, but positively correlated with Ca released from the PRs. Laboratory incubation studies on the release of P from PRs added to soils with or without organic acids and incubated at 25 °C for 15, 30, and 45 days showed that the percentage of plant-available P released varied considerably from 0.95 in the Kodjari PR to 40.1% in the North Carolina PR and was related to PR reactivity. A greenhouse study with corn (Zea mays L.) grown for 60 days on soils treated with PRs or with PRs mixed with organic acids showed that corn response to addition of oxalic or citric acid varied with P rates and PR sources, suggesting that organic acids have potential as amendments for increasing plant-available P in PR-treated soils.     

Soil and vegetation carbon stocks in Brazilian Western Amazonia: relationships and ecological implications for natural landscapes

The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones: Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow soils from the Roraima and Rondonia highlands. A consistent east–west decline in biomass carbon in the Rio Negro Basin sector is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There is a risk of misinterpreting C stocks in Amazonia when such great pedological variability is not taken into account.     

Application of a systemic approach to the study of pollution of the Tinto and Odiel rivers (Spain)

The province of Huelva in the SW of Spain presents high environmental contrasts: together with the great abundance of natural spaces, it shows the impacts of historical natural resources exploitation processes. In the Ria of Huelva, the effluents of the chemical industries must be added to the contaminating inputs of the Tinto and Odiel rivers, coming from the acid drainage of the mines located in the Iberian Pyrite Belt. This forced the Environmental Agency (AMA) to elaborate in 1987 an Effluent Remediation Plan in order to negate unacceptable environmental impacts. The application of a grey box systemic analysis to the AMD pollution, undergone by the Tinto and Odiel rivers has allowed to set a conclusive explanation of the sampling results observed for a period of 11 years, thus making available an overall view of the polluting process and, above all, an explanation of its partial aspects.     

Prenatal sonographic assessment of early,rapidly growing fetal cervical teratoma

Although malignant transformation of fetal cervical teratoma is extremely rare, perinatal morbidity is high and usually related to the size of the tumour, which may compromise fetal swallowing and subsequently lead to upper airway obstruction. We present a case in which mid-trimester serial sonography demonstrated markedly rapid early growth of a lesion of this type between 17 and 19 weeks' gestation indicating the aggressive nature of this tumour, assisting parental decision to terminate the pregnancy. Histopathology confirmed grade 3 immaturity of the lesion.     

Double-labelling methods used to diagnose apoptotic and necrotic cell degradations in copepod nauplii

Two double-labelling methods, Tunel+propidium iodide and Annexin V-FITC+propidium iodide, have been tested to diagnose cell degradation processes in N1–N2 nauplius stages produced by spawning females of the copepod Calanus helgolandicus fed either non-toxic (PRO: control) or toxic (TR1) diets under laboratory conditions. Observation of labelled samples with a confocal laser-scanning microscope revealed that the maternal-food effect, following absorption of the toxic diet, induced cell apoptosis and necrosis in 80–100% of the offspring, which sooner or later died. Similar cell damages were also observed in 18–50% of the nauplii produced by females incubated in filtered seawater. Such cell degradation processes and high mortality were not observed in nauplii produced by females fed the non-toxic diet. Our protocols allowed detection of cell degradations before death of unhealthy larvae, preferentially with a confocal microscope or a conventional visible-fluorescent-light microscope.Communicated by O. Kinne, Oldendorf/Luhe