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 impact on tropospheric ozone formation on the implementation of a program for mobile emissions control: a case study in São Paulo,Brazil

The main sources of reactive hydrocarbons (RHC) and nitrogen oxides (NO_x), ozone precursors, in the Metropolitan Area of São Paulo (MASP) in the southeast of Brazil are emissions from vehicles fleets. Ambient surface ozone and particulate matter concentrations are air quality problem in the MASP. This study examined the impact that implementing a control program for mobile emissions has on ozone concentrations, An episode of high surface ozone concentrations occurring in the MASP during the March 13–15, 2000 period was used as a case study that was modeled for photochemical oxidants using the California Institute of Technology/Carnegie Mellon University three-dimensional photochemical model. Different scenarios were analyzed in relationship to the implementation of the Programa Nacional de Controle de Poluição por Veículos Automotores (PROCONVE, National Program to Control Motor Vehicle Pollution). Scenario 1 assumed that all vehicles were operating within PROCONVE guidelines. Scenarios 2 and 3 considered hypothetical situations in which the PROCONVE was not implemented. Scenario 2 set the premise that vehicles were using pre-1989 technology, whereas scenario 3 allowed for technological advances. A base case scenario, in which the official emission inventory for the year 2000 was employed, was also analyzed. The CIT model results show agreement with most measurements collected during 13–15 March 2000 modeling episode. Mean normalized bias for ozone, CO, RHC and NO _x are approximately 9.0, 6.0, ?8.3, 13.0%, respectively. Tropospheric ozone concentrations predicted for scenario 2 were higher than those predicted for scenarios 1, 3 and base case. This study makes a significant contribution to the evaluation of air quality improvement and provides data for use in evaluating the economic costs of implementing a program of motor vehicle pollution control aimed at protecting human health.     

The impact of a cement company’s CSR programmes on the lifestyles of a rural community: a case study in the Ring 1 area in Tuban,East Java,Indonesia

The studies about patterns and impacts of a company’s corporate social responsibility (CSR) programmes on the local communities have been conducted in a number of developed countries. The similar studies, however, were still rarely conducted in developing countries, particularly in Indonesia. This study aims at discussing the impact of the CSR programmes of a cement company on the lifestyles of a rural community in six villages in Tuban district of East Java Province in Indonesia. The study was conducted from January to September 2015, using qualitative data collection and analysis. This study found that the presence of the cement company has made both positive and negative impacts to the rural community. For the positive impacts, we can see the development of infrastructure that makes the villages become more representative; the emergence of new business opportunities, such as food stalls and boarding houses; and the improvement of the quality of human resources through free health care, education, and religious activities. The supports from the cement company, however, have not been distributed equally among the villagers. In addition, we can also see the following negative impacts: the increase of social tense among the villagers due to the tight competition to obtain work in the cement company; the uneasy relation between the local people and the immigrants who work in the cement company; the decrease in the number of people working in agricultural sectors, as most of them have moved or wish to move to the cement company.     

A molecular approach to the ecology of a mussel (Mytilus edulis – M. trossulus) hybrid zone on the east coast of Newfoundland, Canada

Mytilus trossulus Gould and M. edulis L. coexist in mixed populations in Atlantic Canadian waters. Although there is evidence that the two species hybridize in natural populations and that hybrids produce progeny through backcrosses, no study of the microgeographic distribution of the two forms and their hybrids has been made. Here we examine subtidal samples of mussels taken in July 1997 from two locations in eastern Newfoundland (Canada) and from wave-exposed and protected environments within each location. Shell lengths ranged from 15 to about 90 mm. Mussels were classified as pure forms or hybrids (F₁, F₂ and from backcrosses) based on four diagnostic markers, two allozyme loci (Mpi and Est-D) and two nuclear PCR-based DNA markers (ITS and Glu-5). In addition, a PCR-based mtDNA marker (COIII) was used to characterize the distribution of mtDNA mitotypes among pure and hybrid individuals. There were differences in the proportions of pure M. edulis and M. trossulus between sites and between environments at one location. M. trossulus was the predominant species at one of the two exposed sites. In all four samples, M. trossulus was also the predominant form among small individuals. The frequency of hybrids was 26% overall and did not differ among samples. Hybrids consisted mostly of backcrosses that were M. trossulus-biased among small mussels and M. edulis-biased among large ones. We conclude that both intrinsic genetic factors and extrinsic environmental factors influence the relative frequency of M. edulis, M. trossulus and their hybrids. Received: 29 June 1998 / Accepted: 4 November 1998     

The effects of an extraordinary El Niño / La Niña event on the size and growth of the squid<Emphasis Type="Italic"> Loligo opalescens</Emphasis> off Southern California

The population structure of the California market squid Loligo opalescens was studied for the Channel Islands region off Southern California between June 1998 and March 2000. During this time Californian waters were exposed to an extraordinary El Niño event that was possibly the most dramatic change in oceanographic conditions that occurred last century. There was then a rapid transition to record cool La Niña conditions. Statolith increments were used to determine age parameters and increment periodicity was validated for the first 54 days of life. Based on statolith increment counts, the oldest males and females were 257 and 225 days respectively and individuals matured as young as 129 and 137 days respectively. No distinct hatching period was detected. There was a general trend of increasing body size throughout the study period. Squid that hatched and grew through the El Niño were strikingly smaller and had slower growth rates compared to squid that grew through the La Niña. This was related to oceanography and associated productivity. There was a positive correlation between squid mantle length and upwelling index and a negative correlation between mantle length and sea temperature. The 'live-fast die-young' life history strategy of squid makes them ideal candidates for following the effects of the dramatic changes in oceanographic conditions off California. We propose that squid can serve as ecosystem recorders and productivity integrators over time and space and are useful organisms to tie oceanography to biology.