Efficacy of hydroethanolic extract of Randia aculeata seed against the southern cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) on naturally infested cattle under field conditions.

The cattle tick Rhipicephalus (Boophilus) microplus is a major problem of concern for cattle industry in tropical and subtropical areas. Control of cattle tick is based mainly on the use of chemical acaricides, which has contributed to the emerging problem of selection of resistant tick lineages. Plants have been used as an alternative to conventional acaricidal drugs. On the other hand, the acaricidal activity of hydroethanolic extract of Randia aculeata seed (EHRA) has been demonstrated against R. microplus under laboratory conditions. However, the utility of EHRA seed as a potential acaricidal needs to be determined under field conditions. For this reason, the aim of this study was to evaluate the efficacy of the EHRA against R. microplus sprayed on naturally infested calves, determine the effect of the EHRA seed on acetylcholinesterase activity in R. microplus larval and identify the chemical composition of EHRA. Forty-five male calves were divided in three groups and treated with: G1 water; G2 EHRA 20% w/v and G3 coumaphos 0.2% v/v. Acetylcholinesterase (AChE) activity in R. microplus larvae was determined by a colorimetric assay. The chemical composition of EHRA was accessed through HPLC/MS. Significantly fewer ticks were observed after 24 h on the treated group compared to control group. EHRA significantly inhibited in vitro AChE activity in R. microplus at all tested concentrations. Chlorogenic acid, vanillinic acid, p-coumaric acid, caffeic acid. rutin, quercetin, (-)-epicatechin, 4-hydroxybenzoic acid, quercetin, vanillin, 2,4-dimethoxy-6-methylbenzoic acid, scopoletin and ferulic acid were identified in the extract. The results provided new data for the elucidation of the mechanisms of EHRA acaricide action and to further evaluate the use as a new alternative control agent against R. microplus under in vivo conditions.

Lead acetate ecotoxicity in tropical soils.

Lead acetate (AcPb) is an important raw material used in chemical industries worldwide. The potential toxicity of AcPb is generally attributed to the presence of Pb. However, the effect of AcPb on the environment as a whole is still poorly known. This study aimed to evaluate AcPb toxicity on three standard species of soil invertebrates and two plant species using ecotoxicology tests. Three tropical soils (Oxisol, Inceptisol, and Tropical Artificial Soil (TAS)) were contaminated with different concentrations of AcPb and one dose of K-acetate (positive control). These soils were used in tests with Eisenia andrei (earthworm), Folsomia candida (springtail), Enchytraeus crypticus (enchytraeid), Zea mays (maize), and Phaseolus vulgaris (common bean). Dose-response curves obtained in the laboratory tests were used to estimate the EC50 values for each species. Among invertebrates, the highest sensitivity to AcPb was observed for E. crypticus in the TAS (EC50 = 29.8 mg AcPb kg-1), whereas for E. andrei and F. candida the highest sensitivity was observed in the Oxisol (EC50 = 141.9 and 1835 mg AcPb kg-1, respectively). Folsomia candida was the least sensitive invertebrate species to AcPb in all soils. Among plant species, Z. mays was less sensitive (EC50 = 1527.5 mg AcPb kg-1) than P. vulgaris (EC50 = 560.5 mg AcPb kg-1) in the Oxisol. The present study evidenced that the toxicity of AcPb should not be attributed uniquely to the presence of Pb, as the treatment containing uniquely Ac provoked the same toxicity as the highest dose of AcPb.

Worldwide data sets constrain the water vapor uptake coefficient in cloud formation.

Cloud droplet formation depends on the condensation of water vapor on ambient aerosols, the rate of which is strongly affected by the kinetics of water uptake as expressed by the condensation (or mass accommodation) coefficient, αc. Estimates of αc for droplet growth from activation of ambient particles vary considerably and represent a critical source of uncertainty in estimates of global cloud droplet distributions and the aerosol indirect forcing of climate. We present an analysis of 10 globally relevant data sets of cloud condensation nuclei to constrain the value of αc for ambient aerosol. We find that rapid activation kinetics (αc > 0.1) is uniformly prevalent. This finding resolves a long-standing issue in cloud physics, as the uncertainty in water vapor accommodation on droplets is considerably less than previously thought.

Highway proximity associated with cardiovascular disease risk: the influence of individual-level confounders and exposure misclassification.

BACKGROUND: Elevated cardiovascular disease risk has been reported with proximity to highways or busy roadways, but proximity measures can be challenging to interpret given potential confounders and exposure error. METHODS: We conducted a cross sectional analysis of plasma levels of C-Reactive Protein (hsCRP), Interleukin-6 (IL-6), Tumor Necrosis Factor alpha receptor II (TNF-RII) and fibrinogen with distance of residence to a highway in and around Boston, Massachusetts. Distance was assigned using ortho-photo corrected parcel matching, as well as less precise approaches such as simple parcel matching and geocoding addresses to street networks. We used a combined random and convenience sample of 260 adults >40 years old. We screened a large number of individual-level variables including some infrequently collected for assessment of highway proximity, and included a subset in our final regression models. We monitored ultrafine particle (UFP) levels in the study areas to help interpret proximity measures. RESULTS: Using the orthophoto corrected geocoding, in a fully adjusted model, hsCRP and IL-6 differed by distance category relative to urban background: 43% (-16%,141%) and 49% (6%,110%) increase for 0-50 m; 7% (-39%,45%) and 41% (6%,86%) for 50-150 m; 54% (-2%,142%) and 18% (-11%,57%) for 150-250 m, and 49% (-4%, 131%) and 42% (6%, 89%) for 250-450 m. There was little evidence for association for TNF-RII or fibrinogen. Ortho-photo corrected geocoding resulted in stronger associations than traditional methods which introduced differential misclassification. Restricted analysis found the effect of proximity on biomarkers was mostly downwind from the highway or upwind where there was considerable local street traffic, consistent with patterns of monitored UFP levels. CONCLUSION: We found associations between highway proximity and both hsCRP and IL-6, with non-monotonic patterns explained partly by individual-level factors and differences between proximity and UFP concentrations. Our analyses emphasize the importance of controlling for the risk of differential exposure misclassification from geocoding error.

Particle number emission factors for an urban highway tunnel.

Exposure to traffic-related air pollution has been linked to increased risks of cardiopulmonary disease, asthma, and reduced lung function. Ultrafine particles (UFP; aerodynamic diameter < 100 nm), one component of traffic exhaust, may contribute to these risks. This paper describes the development of UFP emission factors, an important input parameter for dispersion models used for exposure assessment. Measurements of particle number concentration (PNC), a proxy for UFP, were performed in the Central Artery Tunnel on Interstate-93 in Boston (MA, USA). The tunnel system consists of two, unidirectional bores, which each carry ~9 × 104 vehicles per day (diesel vehicles comprise 2-5% of the fleet in the southbound tunnel and 1-3% in the northbound tunnel). A tunnel was chosen for study because it provided an enclosed environment where the effe1cts of lateral and vertical dispersion by ambient air and photochemical reactions would be minimized. Data were collected using a mobile platform equipped with rapid-response instruments for measuring PNC (4-3000 nm) as well as NOx. Because Boston is located in a temperate region (latitude 42° N), we were interested in studying seasonal and diurnal differences in emission factors. To characterize seasonal differences, mobile monitoring was performed on 36 days spaced at 7-14 day intervals over one year (Sept. 2010-Sept. 2011); to characterize diurnal differences intensive mobile monitoring (n = 90 total trips through the tunnels) was performed over the course of two consecutive days in January 2012. All data collected during congested traffic conditions (~7% of total data set) were removed from the analysis. The median PNC inside the two tunnels for all trips during the 12-month campaign was 3-4-fold higher than on I-93 immediately outside the tunnel and 7-10-fold higher than on I-93 4 km from the tunnel. The median particle number emission factors (EFPN) (±median absolute deviation) for the southbound and northbound tunnels were 5.1 × 1014 (2.3 × 1014) and 1.4 × 1014 (4.2 × 1013) particles vehicle-1 km-1, respectively. EFPN values were ~2-fold higher in winter and spring (average ambient temperature at the time of monitoring = 6.9 °C) compared to summer and fall (12.9 °C), and ~2-fold higher in the morning (-7.9 °C) compared to the afternoon/ evening (-0.9 °C) on two consecutive winter days. Our results suggest that seasonal and diurnal variations in particulate emissions from highway vehicles may be important to consider in developing EFPN values.

Clinical presentation and laboratory findings for the first autochthonous cases of dengue fever in Madeira island, Portugal, October 2012.

An outbreak of dengue fever in Madeira island was reported in 2012. Clinical and laboratory findings of the first two laboratory-confirmed autochthonous cases are reported. Both cases had fever (≥38 °C) and petechial rash. Symptoms also included myalgia, asthenia, nausea, vomiting, anorexia, diffuse abdominal pain, and diarrhoea. The two cases were confirmed by serology and one tested positive for a dengue viral sequence. Dengue virus serotype DEN-1 was identified with probable Central or South American origin.

Serological evidence of Toscana virus infection in Portuguese patients.

Toscana virus (TOSV) is an emerging Phlebovirus of growing interest as a human pathogen in the Mediterranean Basin. In Portugal, however, little is known about the prevalence of TOSV infection. The aim of this work was to perform a seroprevalence study in patients with requests for laboratory diagnosis of vector-borne viruses. A total of 538 patients with and without neurological signs from 2004 to 2008 were studied by in-house indirect immunofluorescence assay and commercial enzyme-linked immunosorbent assays. A prevalence of 4.2% for IgG antibodies was found in the group of patients with neurological signs. Five (3%) of these had recent infections. In the group with no neurological signs, the IgG prevalence was 1.3%. Two samples, belonging to two patients, were also confirmed with plaque reduction neutralization tests with the TOSV ISS. Phl.3 Italian strain. This work showed that TOSV is present and causing disease from north to south in Portugal. The probable circulation of different phlebovirus serotypes in Portugal emphasizes the need for further studies.

Mobile monitoring of particle number concentration and other traffic-related air pollutants in a near-highway neighborhood over the course of a year.

Accurate quantification of exposures to traffic-related air pollution in near-highway neighborhoods is challenging due to the high degree of spatial and temporal variation of pollutant levels. The objective of this study was to measure air pollutant levels in a near-highway urban area over a wide range of traffic and meteorological conditions using a mobile monitoring platform. The study was performed in a 2.3-km(2) area in Somerville, Massachusetts (USA), near Interstate I-93, a highway that carries 150,000 vehicles per day. The mobile platform was equipped with rapid-response instruments and was driven repeatedly along a 15.4-km route on 55 days between September 2009 and August 2010. Monitoring was performed in 4-6-hour shifts in the morning, afternoon and evening on both weekdays and weekends in winter, spring, summer and fall. Measurements were made of particle number concentration (PNC; 4-3,000 nm), particle size distribution, fine particle mass (PM(2.5)), particle-bound polycyclic aromatic hydrocarbons (pPAH), black carbon (BC), carbon monoxide (CO), and nitrogen oxides (NO and NO(x)). The highest pollutant concentrations were measured within 0-50 m of I-93 with distance-decay gradients varying depending on traffic and meteorology. The most pronounced variations were observed for PNC. Annual median PNC 0-50 m from I-93 was two-fold higher compared to the background area (>1 km from I-93). In general, PNC levels were highest in winter and lowest in summer and fall, higher on weekdays and Saturdays compared to Sundays, and higher during morning rush hour compared to later in the day. Similar spatial and temporal trends were observed for NO, CO and BC, but not for PM(2.5). Spatial variations in PNC distance-decay gradients were non-uniform largely due to contributions from local street traffic. Hour-to-hour, day-to-day and season-to-season variations in PNC were of the same magnitude as spatial variations. Datasets containing fine-scale temporal and spatial variation of air pollution levels near highways may help to inform exposure assessment efforts.

Boric acid as reference substance: pros, cons and standardization.

Boric acid (BA) has been successfully used as reference substance in some standard test guidelines. Due to the fact that previously selected reference substances present a significant risk to human health and/or are banned for environmental reasons, BA is being discussed for broader adoption in OECD or ISO guidelines. To provide input on BA data and contribute to the discussion on its suitability as a reference substance, in the present study BA was tested with two standard soil organisms, Enchytraeus albidus and Folsomia candida, in terms of survival, reproduction and avoidance. Additionally, published data on other organisms was analysed to derive the most sensitive soil dwelling invertebrate (hazard concentration-HC5). Results showed that BA affected the tested organisms, being two times more toxic for collembolans (LC50 = 96; EC50 = 54 mg/kg) than for enchytraeids (LC50 = 325; EC50 = 104 mg/kg). No avoidance behaviour occurred despite the fact that BA affects earthworms. Actually, it is the recommended reference substance for the earthworm avoidance test. Clearly, the suitable performance of BA in one species should not be generalized to other species. Absolute toxicity is not an important criterion for the selection of a reference substance, but it has been proposed that effects should occur within a reasonable range, i.e. <1,000 mg/kg. We could confirm, compiling previous data that for most soil invertebrates, the EC50 is expected to be below 1,000 mg/kg. From these data it could be derived that the most sensitive soil dwelling invertebrate (HC5, 50%) is likely to be affected (EC10) at 28 (8-53) mg H(3)BO(3)/Kg, equivalent to 4.6 (1.4-8.7) mg boron/kg.

Short-term changes of metal availability in soil. Part I: comparing sludge-amended with metal-spiked soils.

Sewage sludge application to soils is regulated by its total metal content. However, the real risk of metals is determined by the fraction that is biologically available. The available fraction is highly related to the strength of metal binding by the matrix, which is a dynamic process. The evaluation of the fate of metals in time can contribute increased accuracy of ecological risk assessment. Aiming to evaluate short-term changes in metal availability when metals were applied to soil directly (metal-spiked) or by way of an organic matrix (sludge-amended), a laboratory experiment was performed using open microcosms filled with agricultural soil. A concentration gradient of industrial sludge (11, 15, 55, and 75 t/ha) that was contaminated predominantly with chromium, copper, nickel, and zinc, or soil freshly spiked with the same concentrations of these metals, were applied on top of the agricultural soil. After 0, 3, 6, and 12 weeks, total (HNO(3) 69 %) and 0.01 M CaCl(2)-extractable metal concentrations in soil and metal content in the percolates were measured. Results demonstrated that comparison between sludge-amended and metal-spiked soils may give important information about the role of sludge matrix on metal mobility and availability in soil. In sludge-amended soils, extractable-metal concentrations were independent of the sludge concentration and did not change over time. In metal-spiked soils, metal extractability decreased with time due to ageing and transport of metals to deeper layers. In general, the sludge matrix increased the adsorption of metals, thus decreasing their mobility in soils.

Toxicity to Eisenia andrei and Folsomia candida of a metal mixture applied to soil directly or via an organic matrix.

Regulatory limits for chemicals and ecological risk assessment are usually based on the effects of single compounds, not taking into account mixture effects. The ecotoxicity of metal-contaminated sludge may, however, not only be due to its metal content. Both the sludge matrix and the presence of other toxicants may mitigate or promote metal toxicity. To test this assumption, the toxicity of soils recently amended with an industrial sludge predominantly contaminated with chromium, copper, nickel, and zinc and soils freshly spiked with the same mixture of metals was evaluated through earthworm (Eisenia andrei) and collembolan (Folsomia candida) reproduction tests. The sludge was less toxic than the spiked metal mixture for E. andrei but more toxic for F. candida. Results obtained for the earthworms suggest a decrease in metal bioavailability promoted by the high organic matter content of the sludge. The higher toxicity of the sludge for F. candida was probably due to the additive toxic effect of other pollutants.

Predictors of dropout from a multidisciplinary heart failure program: a nested case study.

BACKGROUND: Chronic heart failure is a growing public health issue that is reaching epidemic proportions. In the last few years, multidisciplinary management programs have been developed to improve its management. Yet, some patients take advantage of these programs, whereas others do not. METHODS: Several demographic, medical, and social variables were evaluated as contributors to dropout after enrollment into a multidisciplinary heart failure program using a nested case-control design. A total of 14 patients and 42 controls were interviewed using a standardized questionnaire. Possible associations were explored by means of chi Mantel-Haenszel test and a binary logistic regression model. RESULTS: The only significant factor associated with dropout was social isolation. Patients who lived alone, without family support, had a significantly greater dropout risk (odds ratio, 12.5; 95% confidence interval, 1.35-11.6). CONCLUSIONS: For patients who live alone, an individualized approach may be better than a multidisciplinary management program, but this hypothesis should be investigated in future studies.

A multi-year data set on aerosol-cloud-precipitation-meteorology interactions for marine stratocumulus clouds.

Airborne measurements of meteorological, aerosol, and stratocumulus cloud properties have been harmonized from six field campaigns during July-August months between 2005 and 2016 off the California coast. A consistent set of core instruments was deployed on the Center for Interdisciplinary Remotely-Piloted Aircraft Studies Twin Otter for 113 flight days, amounting to 514 flight hours. A unique aspect of the compiled data set is detailed measurements of aerosol microphysical properties (size distribution, composition, bioaerosol detection, hygroscopicity, optical), cloud water composition, and different sampling inlets to distinguish between clear air aerosol, interstitial in-cloud aerosol, and droplet residual particles in cloud. Measurements and data analysis follow documented methods for quality assurance. The data set is suitable for studies associated with aerosol-cloud-precipitation-meteorology-radiation interactions, especially owing to sharp aerosol perturbations from ship traffic and biomass burning. The data set can be used for model initialization and synergistic application with meteorological models and remote sensing data to improve understanding of the very interactions that comprise the largest uncertainty in the effect of anthropogenic emissions on radiative forcing.

Recycling organic wastes to agricultural land as a way to improve its quality: A field study to evaluate benefits and risks.

A field study was established to assess the effects of a sewage sludge (SS), a mixed municipal solid waste compost (MMSWC) and a compost produced from agricultural wastes (AWC), in a Vertisol, using Lolium multiflorum L. The amendments were applied for two consecutive years: 6, 12 and 24t dry matter ha-1 for SS, and the amendment doses for MMSWC and AWC were calculated to deliver the same amount of organic matter (OM) per unit area. The amendments had significant beneficial effects on some soil properties (e.g. soil OM, NKjeldahl, extractable P and K), and on plant productivity parameters (e.g. biomass yield, chlorophyll, foliar area). For instance, soil OM increased from 0.78% to 1.71, 2.48 and 2.51%, after two consecutive years of application of 24t dry matter ha-1 of SS, MMSWC and AWC, respectively, while the plant biomass obtained increased from 7.75tha-1 to 152.41, 78.14 and 29.26tha-1, for the same amendments. On the plant, effects were more pronounced for SS than for both compost applications, a consequence of its higher capacity to provide N to the plant in a readily available form. However, after two years of application, the effects on soil properties were more noticeable for both composts, as their OM is more resistant to mineralization, which endures their beneficial effects on soil. Cadmium, Cr, Ni and Pb pseudo-total concentrations, were not affected significantly by the application of the organic wastes to soil, in all tested doses, neither their extractability by 0.01M CaCl2. On the contrary, Cu and Zn pseudo-total concentrations increased significantly in the second year of the experiment, following the application of the higher rate of MMSWC and AWC, although their extractability remained very low (<0.5% of their pseudo-total fraction). Trace elements concentrations in the aboveground plant material were lower than their maximum tolerable levels for cattle, used as an indicator of risk of their entry into the human food chain. Despite these results, it is interesting to note that the SS promoted a significant increase in the foliar concentrations of Cu, Ni and Zn that did not happen in composts application, which can be explained by the reduction of the soil pH, as a consequence of SS degradation in soil. Concluding, if this type of organic wastes were to be used in a single application, the rate could be as high as 12 or even 24tha-1, however, if they are to be applied in an annual basis, the application rates should be lowered to assure their safe application (e.g. to 6tha-1). Moreover, it is advisable to use more stable and mature organic wastes, which have longer lasting positive effects on soil characteristics.

A Randomized Cross-over Air Filtration Intervention Trial for Reducing Cardiovascular Health Risks in Residents of Public Housing near a Highway.

Exposure to traffic-generated ultrafine particles (UFP; particles <100 nm) is likely a risk factor for cardiovascular disease. We conducted a trial of high-efficiency particulate arrestance (HEPA) filtration in public housing near a highway. Twenty residents in 19 apartments living <200 m from the highway participated in a randomized, double-blind crossover trial. A HEPA filter unit and a particle counter (measuring particle number concentration (PNC), a proxy for UFP) were installed in living rooms. Participants were exposed to filtered air for 21 days and unfiltered air for 21 days. Blood samples were collected and blood pressure measured at days 0, 21 and 42 after a 12-hour fasting period. Plasma was analyzed for high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor necrosis factor alpha-receptor II (TNF-RII) and fibrinogen. PNC reductions ranging from 21% to 68% were recorded in 15 of the apartments. We observed no significant differences in blood pressure or three of the four biomarkers (hsCRP, fibrinogen, and TNF-RII) measured in participants after 21-day exposure to HEPA-filtered air compared to measurements after 21-day exposure to sham-filtered air. In contrast, IL-6 concentrations were significantly higher following HEPA filtration (0.668 pg/mL; CI = 0.465-0.959) compared to sham filtration. Likewise, PNC adjusted for time activity were associated with increasing IL-6 in 14- and 21-day moving averages, and PNC was associated with decreasing blood pressure in Lags 0, 1 and 2, and in a 3-day moving average. These negative associations were unexpected and could be due to a combination of factors including exposure misclassification, unsuccessful randomization (i.e., IL-6 and use of anti-inflammatory medicines), or uncontrolled confounding. Studies with greater reduction in UFP levels and larger sample sizes are needed. There also needs to be more complete assessment of resident time activity and of outdoor vs. indoor source contributions to UFP exposure. HEPA filtration remains a promising, but not fully realized intervention.

Treatment of recalcitrant wastewater from ethanol and citric acid production using the microalga Chlorella vulgaris and the macrophyte Lemna minuscula.

Laboratory-scale experiments were performed to develop a procedure for biological treatment of recalcitrant anaerobic industrial effluent (from ethanol and citric acid production) using first the microalga Chlorella vulgaris followed by the macrophyte Lemna minuscula. This recalcitrant dark-colored wastewater, containing high levels of organic matter and low pH, prevents the growth of microalgae and macrophytes, and therefore, could not be treated by them. Therefore, the wastewater was diluted to 10% of the original concentration with wash water from the production line. Within 4 days of incubation in the wastewater, C. vulgaris population grew from 5 x 10(5) to 2 x 10(6) cells/mL. This culture reduced ammonium ion (71.6%), phosphorus (28%), and chemical oxygen demand (COD) (61%), and dissolved a floating microbial biofilm after 5 days of incubation. Consequently, L. minuscule was able to grow in the treated wastewater (from 7 to 14 g/bioreactor after 6 days), precipitated the microalgal cells (by shading the culture), and reduced other organic matter and color (up to 52%) after an additional 6 days of incubation. However, L. minuscula did not improve removal of nutrients. This study demonstrates the feasibility of combining microalgae and macrophytes for bioremediation of recalcitrant industrial wastewater.

In-home air filtration for improving cardiovascular health: lessons from a CBPR study in public housing.

BACKGROUND: Particulate air pollution, including from motor vehicles, is associated with cardiovascular disease. OBJECTIVES: To describe lessons learned from installing air filtration units in public housing apartments next to a major highway. METHODS: We reviewed experience with recruitment, retention, and acceptance of the air filtration units. RESULTS: Recruitment and retention have been challenging, but similar to other studies in public housing. Equipment noise and overheated apartments during hot weather have been notable complaints from participants. In addition, we found that families with members with Alzheimer's or mental disability were less able to tolerate the equipment. CONCLUSIONS: For this research, the primary lesson is that working closely with each participant is important. A future public health program would need to address issues of noise and heat to make the intervention more acceptable to residents.

Parasitosis intestinales en Altragracia de la Montaña, Estado Miranda, Venezuela: Influencia del programa para la eliminación de oncocercosis / Intestinal parasites in Altragracia de la Montaña, Miranda State, Venezuela: Influence of the program for onchocerciasis elimination

El objetivo general de este trabajo fue determinar la prevalencia de parasitosis intestinales y sus características epidemiológicas en cuatro comunidades de la parroquia Altagracia de la Montaña, Estado Miranda (Venezuela). Se desarrolló un estudio de corte transversal con una muestra constituida por 492 en su mayoría niños, en febrero de 2011. Previo consentimiento informado, se realizó una encuesta clínico-epidemiológica, extracción de sangre y exámenes coproparasitológicos con los métodos directo, Kato y cultivo en agar. El 60% de la población tenía al menos un parásito de transmisión hídrica y/o alimentos contaminados por heces de humanos y/o animales. La elevada frecuencia de protozoarios intestinales, especialmente Blastocystis sp., con predominio entre quienes viven con fallas en la disposición de excretas y baja calidad del agua para consumo humano, demuestran la persistencia de parasitosis intestinales como problema de salud pública; sin embargo, la influencia indirecta de la administración semestral de ivermectina y educación sanitaria con visión etnográfica impartida por el Programa para la Eliminación de Oncocercosis en Bucarito, una de las comunidades evaluadas, tuvo como efecto colateral no sólo disminuir la prevalencia de helmintos intestinales, sino de los protozoarios, a pesar de estar sometida a los mismos factores de riesgo que las comunidades restantes.

The aim of this study was to determine the prevalence of intestinal parasites and their epidemiological characteristics in four rural communities from Altagracia de la Montaña, Miranda State (Venezuela). A cross sectional study was conducted in February 2011 where 492 subjects were evaluated, mostly children. Informed consent was previously obtained. A clinical and epidemiological survey was done. Patients voluntarily brought a fresh stool sample for analysis with direct smear, Kato and agar culture; blood was extracted for eosinophil count. 60% of the evaluated people had at least one parasite transmitted by water or food contaminated by human or animal feces. The high prevalence of protozoa, specially Blastocystis sp., among those who live under poor living conditions such as inadequate feces disposal and low quality of drinking water, shows the persistence of intestinal parasites as a public health problem; nevertheless, indirect influence of ivermectin treatment every six months and health education with an ethnographic orientation given by the Onchocerciasis Elimination Programme in Bucarito, one of the evaluated communities, had an unexpected outcome not only diminishing the prevalence of helminthes but also the prevalence of intestinal protozoa, being this community under the same risk factors as the rest of the evaluated communities.

The use of Collembola avoidance tests to characterize sewage sludges as soil amendments.

The ecotoxicological characterization of sewage sludge takes into account the additive, antagonistic and synergistic effects that occur as a result of multi-chemical interactions. Such an evaluation therefore is essential to complement the chemical analysis that, although required by law, is clearly insufficient. Using a tiered approach in the toxic evaluation of sewage sludge allows for characterization of toxicity in a timely manner. According to the literature, reproduction tests with Folsomia candida are suitable tools for the toxic assessment of organic sludges. Therefore, the inclusion of Collembola avoidance tests at a screening level (low tier), and acting as a trigger for longer-period tests (high tier; e.g. reproduction test), may provide a successful strategy, and may complement the currently proposed test battery. To evaluate the use of both avoidance and reproduction tests with collembolans in such a tiered approach, three sewage sludges (urban, olive and electroplating industries) were mixed in with a field-collected soil at different concentrations. Avoidance and reproduction tests were performed with the soil-sludge mixtures after 0, 4 and 12 weeks of incubation. The tests detected no toxicity in soil-sludge mixtures of urban and olive sludges at any incubation period. Mixtures with sludge from the electroplating industry induced toxicity only in the avoidance tests with freshly prepared and 4-week incubated samples. These results demonstrate the ability of Collembola avoidance tests to assess sewage sludge toxicity over time and its potential for hazardous sludge characterization at low tier levels.