Barriers to evidence use for sustainability: Insights from pesticide policy and practice

Calls for supporting sustainability through more and better research rest on an incomplete understanding of scientific evidence use. We argue that a variety of barriers to a transformative impact of evidence arises from diverse actor motivations within different stages of evidence use. We abductively specify this variety in policy and practice arenas for three actor motivations (truth-seeking, sense-making, and utility-maximizing) and five stages (evidence production, uptake, influence on decisions, effects on sustainability outcomes, and feedback from outcome evaluations). Our interdisciplinary synthesis focuses on the sustainability challenge of reducing environmental and human health risks of agricultural pesticides. It identifies barriers resulting from (1) truth-seekers’ desire to reduce uncertainty that is complicated by evidence gaps, (2) sense-makers’ evidence needs that differ from the type of evidence available, and (3) utility-maximizers’ interests that guide strategic evidence use. We outline context-specific research–policy–practice measures to increase evidence use for sustainable transformation in pesticides and beyond.     

Mercury in the Mediterranean. Part 2: processes and mass balance

Mass balance of contaminants can provide useful information on the processes that influence their concentrations in various environmental compartments. The most important sources, sinks and the equilibrium or non-equilibrium state of the contaminant in individual environmental compartments can also be identified. Using the latest mercury speciation data, the results of numerical models and the results of recent studies on mercury transport and transformation processes in the marine environment, we have re-evaluated the total mercury (HgT) mass balance in the Mediterranean Sea. New calculations have been performed employing three distinct marine layers: the surface layer, the thermocline and the deep sea. New transport mechanisms, deep water formation and density-driven sinking and upwelling, were included in the mass balance calculations. The most recent data have even enabled the calculation of an approximate methylmercury (MeHg) mass balance. HgT is well balanced in the entire Mediterranean, and the discrepancies between inputs and outputs in individual layers do not exceed 20 %. The MeHg balance shows larger discrepancies between gains and losses due to measurement uncertainties and gaps in our knowledge of Hg species transformation processes. Nonetheless, the main sources and sinks of HgT (deposition and evasion) and MeHg (fluxes from sediment, outflow through the Gibraltar Strait) are in accordance with previous studies on mercury in the Mediterranean Basin. Mercury in the Mediterranean fish harvest is the second largest MeHg sink; about 300 kg of this toxic substance is consumed annually with sea food.     

Mercury in the Mediterranean,part I: spatial and temporal trends

The present paper provides an overview of mercury studies performed in the Mediterranean Sea region in the framework of several research projects funded by the European Commission and on-going national programmes carried out during the last 15 years. These studies investigated the temporal and spatial distribution of mercury species in air, in the water column and sediments, and the transport mechanisms connecting them. It was found that atmospheric concentrations of Hg compounds, particularly oxidised Hg species observed at five coastal sites in the Mediterranean Sea Basin, are significantly higher compared with those recorded at five coastal sites distributed across N Europe, most probably due to natural emissions. Hg levels in water are comparable to other oceans. Anthropogenic and natural point sources show locally limited enrichments, while natural diffusive sources influence Hg speciation over larger areas. Results and statistic comparison of mercury species concentrations within Mediterranean compartments will be presented and discussed.     

Influence of nutritional status on some toxic and essential elements in the blood of women exposed to vehicular pollution in Ile-Ife, Nigeria

Blood levels of the elements Cu, Zn, Se, As, Cd, Hg, and Pb have been determined in 62 Nigerian women who were occupationally exposed to vehicular pollution. Mercury was determined using a direct mercury analyzer, while all the other elements were determined by an inductively coupled plasma mass spectrometer system. The mean values for all the toxic elements were all within the recommended desirable/tolerable limits, except for Se (0.44 μg/mL, compared with <0.2 μg/mL recommended by the WHO). More than 98 % of the subjects had blood selenium levels higher than this recommended limit. For As, Hg, and Pb, the corresponding figures of subjects with blood levels above the recommended limits were 4, 8, and 19.3 %, respectively. When the subjects were grouped according to their body mass indexes as normal, underweight, overweight, and obese, analysis of variance shows that mean blood levels of Cu, As, and, to some extent Hg were significantly different in the four nutritional status groups. Blood Hg level correlates significantly with blood As in all the groups, except in obese subjects. Also, a significant correlation between age and blood Hg was observed only in normal subjects and between age and blood Pb only in obese subjects. These results suggest that nutritional status could influence both elemental levels and the interactions between trace elements in the blood of female subjects. Nutrition is therefore a factor to consider in efforts to modify human susceptibility to toxic elements.     

Flue gas desulfurization gypsum and coal fly ash as basic components of prefabricated building materials

The manufacture of prefabricated building materials containing binding products such as ettringite (6CaO·Al₂O₃·3SO₃·32H₂O) and calcium silicate hydrate (CSH) can give, in addition to other well-defined industrial activities, the opportunity of using wastes and by-products as raw materials, thus contributing to further saving of natural resources and protection of the environment.Two ternary mixtures, composed by 40% flue gas desulfurization (FGD) gypsum or natural gypsum (as a reference material), 35% calcium hydroxide and 25% coal fly ash, were submitted to laboratory hydrothermal treatments carried out within time and temperature ranges of 2 h–7 days and 55–85 °C, respectively. The formation of (i) ettringite, by hydration of calcium sulfate given by FGD or natural gypsum, alumina of fly ash and part of calcium hydroxide, and (ii) CSH, by hydration of silica contained in fly ash and residual lime, was observed within both the reacting systems. For the FGD gypsum-based mixture, the conversion toward ettringite and CSH was highest at 70 °C and increased with curing time. Some discrepancies in the hydration behavior between the mixtures were ascribed to differences in mineralogical composition between natural and FGD gypsum.     

Mercury fractionation in contaminated soils from the Idrija mercury mine region

Mercury (Hg) fractionation was investigated in contaminated soil in the Idrija Hg-mine region, Slovenia. The main aim of this study was to test and apply sequential extraction and quantification of different Hg phases in order to estimate the mobility and potential bioavailability of Hg in contaminated soils. Separation of Hg phases was performed by means of a selective sequential extraction procedure complemented by volatilization of elemental mercury (Hg0). The influence of temperature, moisture and storage on Hg0 volatilization was also investigated. The total Hg concentrations varied between 8.4 and 415 mg kg(-1) and were up to 40-fold higher than the maximum permissible set by Slovenian legislation. Fractionation measurements indicated cinnabar as the predominant Hg fraction, followed by Hg0. Accumulation of cinnabar predominantly occurred in coarse grained flood plain sediments, where on average it constituted more than 80% of total Hg. In contrast non-cinnabar fractions were found to be enriched in areas where fine grained material was deposited, reaching up to 60% of total Hg. The strong positive correlation (R2 = 0.71-0.99) among non-cinnabar fractions suggested that these fractions predominantly control the mobility and potential bioavailability of Hg. Sample pretreatment before fractionation influenced the partition of Hg between different fractions, and therefore fractionation in fresh, nontreated samples is suggested. In addition, the specificity of the extraction steps needs further attention, as it was shown that some extraction steps, such as the organo-chelating Hg fraction, do not provide meaningful results. This further suggests that protocols for mercury fractionation need further harmonization in order to improve the comparability of the results and their use in risk assessment. Volatile mercury fluxes averaged between 0.04 and 6.5 ng g(-1) h(-1). Good agreement (R2 = 0.81-0.95) was found between the non-cinnabar fractions and evaporation of Hg0. Both the temperature and sample moisture had significant effects on mercury volatilization. The results in this study were obtained at 70 degrees C, which may be somewhat high, in particular for bacterial activity which may also play an important role in Hg volatilization. Therefore it is strongly suggested that further optimisation of the protocol to assess Hg volatilization from soil is required.     

Evidence of the impacts of the national housing programme on the accessibility of the low‐income population in Rio de Janeiro

The Brazilian shift from a primarily rural to a more urban society has created major challenges that public policies must address. One of the most relevant challenges is deep social exclusion in urban areas, especially in terms of adequate housing and access to urban opportunities (e.g., jobs, housing, and services). In this context, land use and transport planning play a critical role in the sustainable development agenda. The work presented here analyses the accessibility of low‐income dwellings licenced under the Brazilian housing programme to the low‐income population. To evaluate the accessibility of the programme's target population, a case study was conducted in the city of Rio de Janeiro, where 58,000 homes licensed under the programme were analysed using GIS tools in terms of the present public transport network and the location of the homes. The amount of time it takes to access public transport on foot and the homes’ locations in relation to major urban opportunities were also analysed. Finally, the same analysis was performed for the future transport network, and the results of the two analyses were compared to identify the scope of the legacy generated by investments in preparation for the 2016 network.     

Structural factors influencing conservation decision-making: a case of species prioritisation in Australia

Prioritisation methods have been adopted for >20 years to inform resource allocation in species conservation. The academic literature on prioritisation focuses on technical matters, with little attention to the socio-political factors affecting the uptake of priorities. We investigated the policy instruments employed to promote uptake, and the structural factors affecting the uptake of priorities, using as our case study a species prioritisation method adopted by the Queensland Government (Australia). We interviewed 79 key informants and analysed policy documents and plans. The Queensland Government relied on ‘information delivery’ as a policy instrument to foster uptake. We identified communication channels to assist ‘information delivery’ between Government and intended users, but also found that several structural factors limited their use: fragmentation of policies, the relative strength of alternative priorities and centralisation of power in decision-making. We discuss the results in relation to other conservation planning initiatives and suggest how structural barriers can be addressed.     

Cartilage chondroprotection and repair with pulsed electromagnetic fields: I-ONE therapy

Articular cartilage is a complex tissue characterised by chondrocytes that are embedded within an organised dense extracellular matrix of collagen and proteoglycan. Under physiologic condition, articular metabolism is slow, but under pathological condition turnover can increase and the matrix undergoes faster mechanical failure and deterioration, resulting in cartilage degeneration. Moreover, modest damage of the articular cartilage, resulting from trauma or less invasive surgical procedure, produces an inflammatory reaction of the joint cartilage, which can cause irreversible degeneration through the increase in catabolic cytokines synthesis and the decrease in anabolic activity of chondrocytes. Pro-inflammatory cytokines increase the synthesis of matrix-degrading enzymes and limit the production of proteoglycans. It is known that physical stimuli modulate cartilage metabolism. In particular, pulsed electromagnetic fields (I-ONE therapy, Igea, Carpi, Italy) allow to treat homogenously the whole cartilage surface and thickness and the underlying subchondral bone. In vitro I-ONE therapy increases the binding between adenosine and A_2A adenosine receptor on human neutrophils cell membrane, on bovine chondrocytes and on fibroblast-like synoviocytes. It has been shown that drugs with A_2A adenosine receptor agonist activity prevent articular cartilage degeneration in animals. We hypothesised that the adenosine agonist effect of I-ONE therapy can also prevent cartilage degeneration. In a recent study, De Mattei et al. demonstrated how I-ONE therapy can strongly inhibit the release of PGE₂ in bovine synovial fibroblasts exerting an anti-apoptotic effect on cells. Ex vitro, in bovine full thickness articular cartilage explants, I-ONE therapy induces the largest increase in proteoglycan synthesis and in IGF-1 synthesis, when cartilage is exposed to specific parameters of pulsed electromagnetic fields. These effective parameters were subsequently used in in vivo experiments. The effect of I-ONE therapy was investigated on Dunkin Hartley osteoarthritic knee by Mankin score and by histomorphometric and densitometric analysis; I-ONE therapy prevented cartilage degeneration and subchondral bone sclerosis. Osteochondral grafts were performed in the knees of sheep; I-ONE therapy favoured osteochondral grafts integration and prevented cyst-like resorption area formation, which can compromise the stability of graft and the success of the technique. To support the in vitro results, biochemical analyses of the synovial fluid were also performed in this animal model. The amount of inflammatory catabolic cytokines (IL-1β and TNF-α) in the synovial fluid of I-ONE treated animals was significantly lower than in control animals. On the contrary, TGF-β1 was significantly higher in stimulated animals than it was in controls. These results demonstrate not only the capability of I-ONE therapy to control the inflammatory reaction but also its capability to favour cartilage anabolic activity. These results provide the rational to design clinical studies to demonstrate the possibility to transfer the treatment to humans. Two randomised, prospective, double-blind clinical studies (Level I), one conducted to patients treated by arthroscopy with condroabrasion and/or perforations at the knee and the other after anterior cruciate ligament reconstruction, demonstrated that biophysical stimulation with I-ONE therapy leads to complete patient’s recovery in a significantly shorter time (P < 0.005). Moreover, a significant number of treated patients made lower use of anti-inflammatory drugs than the patients in the placebo group. We did not observe negative side effects, patient’s compliance was good and treatment was well accepted. I-ONE therapy significantly reduces patients’ recovery time, joint swelling and has a chondroprotective effect over articular cartilage. I-ONE treatment is a new therapy for the joint preservation.     

Role of volcanic dust in the atmospheric transport and deposition of polycyclic aromatic hydrocarbons and mercury

The role of volcanic ash as scavenger of atmospheric pollutants, in their transport and final deposition to the ground is examined. Attention is focused on polycyclic aromatic hydrocarbons (PAHs) and on particulate mercury (Hgp). The ash-fall deposits studied belong to the 2001 and 2002 eruptive activity of Mount Etna, Southern Italy, and were investigated at three (2001) and four (2002) sites downwind of the major tephra dispersal pattern. The dry deposition of mercury and PAHs was determined, and, in particular, a downward flux to the ground of PAHs (approximately 7.29 microg m(-2) per day) and mercury (750 ng m(-2) per day) was estimated in Catania from October 26 to October 28, 2002. Finally, evidence on the anthropogenic origin of PAHs scavenged from the troposphere by volcanic ash is supported by the analysis of PAH compositions in granulometrically homogeneous fractions.