Μg Day Research Articles

High-risk prescribing in an Irish primary care population: trends and variation.

The aims of the present study were to examine the prevalence of high-risk prescribing (HRP) in community-dwelling adults in Ireland from 2011-2015 using consensus-validated indicators, factors associated with HRP, and the variation in HRP between general practitioners (GPs) and in the dispensing of high-risk prescriptions between pharmacies. A repeated cross-sectional national pharmacy claims database study was conducted. Prescribing indicators were based on those developed in formal consensus studies and applicable to pharmacy claims data. Multilevel logistic regression was used to examine factors associated with HRP and dispensing. There were significant reductions in the rates of most indicators over time (P < 0.001). A total of 66 022 of 300 906 patients at risk in 2011 [21.9%, 95% confidence interval (CI) 21.8, 22.1%], and 42 109 of 278 469 in 2015 (15.1%, 95% CI 15.0, 15.3%), received ≥1 high-risk prescription (P < 0.001). In 2015, indicators with the highest rates of HRP were prescription of a nonsteroidal anti-inflammatory drug (NSAID) without gastroprotection in those ≥75years (37.2% of those on NSAIDs), coprescription of warfarin and an antiplatelet agent or high-risk antibiotic (19.5% and 16.2% of those on warfarin, respectively) and prescription of digoxin ≥250 μg day-1 in those ≥65years (14.0% of those on digoxin). Any HRP increased significantly with age and number of chronic medications (P < 0.001). a) After controlling for patient variables, the variation in the rate of HRP between GPs was significant (P < 0.05); and b) after controlling for patient variables and the prescribing GP, the variation in the rate of dispensing of high-risk prescriptions between pharmacies was significant (P < 0.05). HRP in Ireland has declined over time, although some indicators persist. The variation between GPs and pharmacies suggests the potential for improvement in safe medicines use in community care, particularly in vulnerable older populations.

Quantification of Element Fluxes in Wastewaters: A Nationwide Survey in Switzerland.

The number and quantities of trace elements used in industry, (high-tech) consumer products, and medicine are rapidly increasing, but the resulting emissions and waste streams are largely unknown. We assessed the concentrations of 69 elements in digested sewage sludge and effluent samples from 64 municipal wastewater treatment plants as well as in major rivers in Switzerland. This data set, representative of an entire industrialized country, presents a reference point for current element concentrations, average per-capita fluxes, loads discharged to surface waters, and economic waste-stream values. The spatial distribution of many individual elements could be attributed either to predominant geogenic or to anthropogenic inputs. Per-capita element fluxes ranged from <10 μg day-1 (e.g., Au, In, and Lu) to >1 mg day-1 (e.g., Zn, Sc, Y, Nb, and Gd) and >1 g day-1 (e.g., for P, Fe, and S). Effluent loads of some elements contributed significantly to riverine budgets (e.g., 24% for Zn, 50% for P, and 83% for Gd), indicating large anthropogenic inputs via the wastewater stream. At various locations, precious metal concentrations in sludge were similar to those in profitable mining ores, with total flux values of up to 6.8 USD per capita per year or 15 USD per metric ton of dry sludge.

Copper Oxide Nanoparticle Foliar Uptake, Phytotoxicity, and Consequences for Sustainable Urban Agriculture.

Throughout the world, urban agriculture supplies fresh local vegetables to city populations. However, the increasing anthropogenic uses of metal-containing nanoparticles (NPs) such as CuO-NPs in urban areas may contaminate vegetables through foliar uptake. This study focused on the CuO-NP transfer processes in leafy edible vegetables (i.e., lettuce and cabbage) to assess their potential phytotoxicity. Vegetables were exposed via leaves for 5, 10, or 15 days to various concentrations of CuO-NPs (0, 10, or 250 mg per plant). Biomass and gas exchange values were determined in relation to the Cu uptake rate, localization, and Cu speciation within the plant tissues. High foliar Cu uptake occurred after exposure for 15 days for lettuce [3773 mg (kg of dry weight)-1] and cabbage [4448 mg (kg of dry weight)-1], along with (i) decreased plant weight, net photosynthesis level, and water content and (ii) necrotic Cu-rich areas near deformed stomata containing CuO-NPs observed by scanning electron microscopy and energy dispersive X-ray microanalysis. Analysis of the CuO-NP transfer rate (7.8-242 μg day-1), translocation of Cu from leaves to roots and Cu speciation biotransformation in leaf tissues using electron paramagnetic resonance, suggests the involvement of plant Cu regulation processes. Finally, a potential health risk associated with consumption of vegetables contaminated with CuO-NPs was highlighted.

Dietary strategies for achieving adequate vitamin D and iron intakes in young children in Ireland.

Inadequate intakes of vitamin D and iron have been reported in young children in Ireland. The present study aimed to identify the main foods determining vitamin D and iron intakes and to model the impact of dietary strategies to improve adequacy of these micronutrients in young children. The present study is based on the Irish National Pre-School Nutrition Survey (NPNS), which estimated food and nutrient intakes in a representative sample (n=500) of children (aged 1-4years) using a 4-day weighed food record. Dietary strategies were modelled using DaDiet© software (Dazult Ltd, Co. Kildare, Republic of Ireland) and the usual intake distribution, prevalence of inadequate intakes and risk of excessive intakes were estimated using the National Cancer Institute method. Fortified foods and nutritional supplements were the key foods influencing the intakes of vitamin D and iron. Adding a 5μgday-1 vitamin D supplement, fortifying cow's milk (CM) with vitamin D or replacing CM with growing-up milk (GUM) would modestly increase intakes of vitamin D. A combined strategy of fortifying CM with vitamin D or replacing CM with GUM plus a 5μgday-1 vitamin D supplement would increase mean intakes of vitamin D (from 3.5μgday-1 at baseline to ≥11μgday-1 ) and substantially reduce the prevalence of inadequate intakes (from >95% to 12-36%). Fortifying CM with iron or replacing CM with GUM would increase mean intakes of iron (from 7.3mgday-1 to >10mgday-1 ), achieving adequate intakes across all ages. Based on real food consumption data in a representative sample of Irish children, we have shown that through targeted dietary strategies adequate intakes of iron are achievable and intakes of vitamin D could be greatly improved.

Trace elements in native and improved paddy rice from different climatic regions of Sri Lanka: implications for public health.

BackgroundSamples of 226 new improved and 21 indigenous rice (Oryza sativa L.) varieties were collected from the rice fields in three climatic zones of Sri Lanka and concentrations of 18 trace elements (Li, B, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Ba, Pb and Bi) were measured giving particular emphasis on Se, Cd and As using ICP-MS. The two way multivariate analysis of variance (MANOVA) method was employed to identify the differences in composition among rice from different climatic zones.ResultsThe mean values obtained for both white and red rice were Se (36; 25 µg/kg), As (42; 45 µg/kg) and Cd (70; 123 µg/kg) on dry weight basis. However mean content of Se, As and Cd of native rice varieties were 69, 74 and 33 µg/kg, respectively. Statistical interpretations showed that in the majority of cases, there was a significant difference in Cd content among climatic zones whereas Se and Pb show differences between white and red rice varieties. Arsenic did not indicate any significant difference either between rice types or among climatic regions. Notably Se and As contents in indigenous rice were higher than that of improved rice types. To assess the safety of dietary of intake, daily intake of Se, Cd and As by rice were calculated. Non-gender specific Estimated Daily Intake (EDI) of Se, Cd and As consuming improved rice are 9.31, 24.1 and 12.2 µg day−1, respectively.ConclusionsSince over 50 % of daily meals of people contain rice or rice based products, Se intake is expected to be deficient among the Sri Lankan population.

Quantification of iodine loss in edible Irish seaweeds during processing

Exposure to seaweed-derived iodine through the consumption of macroalgae can positively and negatively influence human health, depending on whether adequate (150 μg day−1) or excessive quantities are ingested. Following harvest, macroalgal material typically undergoes certain processing procedures involving washing, dehydration, rehydration (soaking) and cooking (boiling) before it is consumed. In this study, we assessed iodine in edible brown (Alaria esculenta), red (Palmaria palmata) and green (Ulva intestinalis) macroalgae and quantified the iodine loss during processing. Freshly collected A. esculenta contained higher quantities of iodine (670 μg (g dw)−1) than P. palmata (97 μg (g dw)−1) and U. intestinalis (92 μg (g dw)−1), implying that only 0.2–1.6 g dw of freshly harvested algae contain the recommended daily intake level. Washing (10 min in deionised water) and dehydration (air-, oven- and freeze-drying) at low irradiances only marginally affected iodine levels, suggesting that gentle preservation techniques prevent iodine loss. By contrast, rehydration (1–24 h soaking in deionised water) significantly reduced iodine: by 62 % in A. esculenta, by 15 % in P. palmata and by 10 % in U. intestinalis. The iodine levels of all three species decreased further upon boiling (20 min in deionised water). Despite a considerable, but species-specific, loss of iodine during processing, all macroalgae still contained iodine at 66 to 165 μg (g dw)−1 after rehydration and subsequent boiling. Our results indicate that both raw and processed macroalgae can be considered as a rich source of iodine and thus their consumption may influence human health and nutrition.

Effects of intracerebroventricular infusions of ghrelin on secretion of follicle-stimulating hormone in peripubertal female sheep.

Reproduction depends on mechanisms responsible for the regulation of energy homeostasis and puberty is a developmental period when reproductive and somatic maturity are achieved. Ghrelin affects the activity of the hypothalamo-pituitary-gonadal axis under conditions of energy insufficiency. An in vivo model based on intracerebroventricular (i.c.v.) infusions was used to determine whether centrally administered acyl ghrelin affects transcriptional and translational activity of FSH in peripubertal lambs and whether ghrelin administration mimics the effects of short-term fasting. Standard-fed lambs received either Ringer-Lock (R-L) solution (120µL h-1) or ghrelin (120µL h-1, 100µg day-1). Animals experiencing a short-term (72h) fast were treated only with R-L solution. In each experimental group, i.c.v. infusions occurred for 3 consecutive days. Immunohistochemistry, in situ hybridisation and real-time reverse transcription quantitative polymerase chain reaction analyses revealed that short-term fasting, as well as exogenous acyl ghrelin administration to standard-fed peripubertal lambs, augmented FSHβ mRNA expression and immunoreactive FSH accumulation. In addition to the effects of ghrelin on FSH synthesis in standard-fed animals, effects on gonadotrophin release were also observed. Acyl ghrelin increased the pulse amplitude for gonadotrophin release, which resulted in an elevation in mean serum FSH concentrations. In conclusion, the present data suggest that ghrelin participates in an endocrine network that modulates gonadotrophic activity in peripubertal female sheep.

Detection and Quantification of Benzothiazoles in Exhaled Breath and Exhaled Breath Condensate by Real-Time Secondary Electrospray Ionization-High-Resolution Mass Spectrometry and Ultra-High Performance Liquid Chromatography.

2-Subtituted benzothiazoles are widely used industrial chemicals whose occurrence in environmental samples has been shown to be ubiquitous. However, knowledge about human exposure to these compounds and their excretion route is still scarce. Here, we demonstrate for the first time the detection of benzothiazole derivatives in exhaled breath. Real-time analysis of breath was carried out by means of secondary electrospray ionization coupled to high-resolution mass spectrometry. This coupling allowed not only the detection of these compounds in breath with a sensitivity in the pptv range but also their robust identification by comparing tandem high-resolution mass spectra from breath and standards. For further confirmation, benzothiazoles were also determined in exhaled breath condensate samples by means of ultra high-performance liquid chromatography. This approach strengthened the identification as a result of excellent matches in retention times and also allowed quantification. An estimated total daily exhalation of ca. 20 μg day(-1) was calculated for the six benzothiazole derivatives found in breath.

Validation of a food frequency questionnaire to determine vitamin D intakes using the method of triads.

Dietary sources of vitamin D (both natural and fortified) are increasingly contributing to consumers' vitamin D intake and status. Therefore, the present study aimed to validate a vitamin D food frequency questionnaire (FFQ) for the assessment of habitual vitamin D intake. A total of 49 apparently healthy consenting adults (aged 18-64 years) from the local community were sampled at the end of winter. Dietary intakes were recorded using a 4-day weighed food record (4d-WFR) and a 17-item FFQ based on foods known to contribute to dietary vitamin D intake. Fasting vitamin D status was quantified by serum 25-hydroxyvitamin D [25(OH)D] using liquid chromatography tandem mass spectrometry. The method of triads was applied using these three measurements to determine the overall validity of the FFQ. Vitamin D intakes from 4d-WFR ranged between 0.42 and 31.65 μg day(-1), whereas intakes determined from the FFQ ranged from 1.03 to 36.08 μg day(-1). Serum 25(OH)D concentrations ranged between 12.89 and 279.00 nmol L(-1). The mean (SD) difference between the FFQ and 4d-WFR was +1.62 ( 3.86). There were strong correlations between the vitamin D intake estimated by the FFQ and that from the 4d-WFR (r = 0.562) and also with serum 25(OH)D concentrations (r = 0.567). Vitamin D intake estimated from the 4d-WFR was also strongly correlated with serum 25(OH)D concentrations (r = 0.411). The overall validity coefficient calculated using the method of triads was high (0.881). The vitamin D FFQ has been validated for use in future studies aiming to assess habitual vitamin D intake.

Determination of 4(5)-methylimidazole in carbonated beverages by isotope-dilution liquid chromatography-tandem mass spectrometry

The purpose of this study was to develop a method to quantify 4(5)-methylimidazole (4-MEI), a suspected carcinogen, in carbonated beverages by simple sample dilution and isotope-dilution reverse-phase LC-MS/MS. Isotope dilution using hexa-deuterated methylimidazole (d6-4-MEI) was used to quantify native 4-MEI and to assess matrix effects quantitatively. The accuracy of the method was assessed by intentionally fortifying a negative control sample at three doses: low, medium and high (replicates of n = 5 each) with a known amount of 4-MEI. The respective absolute error in each case was 18.7 ± 0.7%, 14.6 ± 2.8% and 21.1 ± 9.7%. Within-day (intra-) and day-to-day (inter-) repeatability, determined as the relative standard deviation by fortifying a negative control sample (n = 5), were 9.5% and 15.4%, respectively. Average ion suppression of d6-4-MEI in beer was 63.9 ± 3.2%, while no suppression or enhancement was seen in non-alcoholic samples. The instrument and method limit of detection were calculated as 0.6 and 5.8 ng ml–1, respectively. 4(5)-Methylimidazole was quantified in a variety of store-bought consumer beverages and it was found that in many of the samples tested consuming a single can of beer would result in intake levels of 4-MEI that exceed the no significant risk guideline of 29 µg day–1. Conversely, 4-MEI in the samples was orders of magnitude smaller than the European Food Safety Authority acceptable daily intake threshold value of 100 mg kg–1 bw day–1.

Quantification of oxytocin residues in dairy milk from Sindh, Pakistan

SummaryIn this study, a total of 84 milk samples (60 nonbranded and 24 branded) were analysed for occurrence of oxytocin (OT) residues by ELISA. OT level was detected in the range of 39.29–456.55 pg mL−1 with mean value of 138.53 ng L−1. In branded milk samples, OT residues were minimal as compared to nonbranded milk samples. Nonbranded milk samples had higher prevalence of OT residues; 16.67% had OT level in the range of ≤500 ng L−1. The average daily intake of OT was found 0.087 μg day−1 per person. It was concluded that the OT concentration was relatively higher in samples obtained from dairy farm, dairy shop and milk man than that in ultra‐high temperature (UHT) and powder milk samples. In addition, there are no reports subjected to standardising a permissible OT level in dairy milk category, although OT is considered detrimental to both human and animal life.

High- and low-dose allergen challenges in asthmatic patients using inhaled corticosteroids.

The inhaled allergen challenge model has been used previously to investigate the effects of novel anti-inflammatory drugs in inhaled corticosteroid (ICS)-naïve asthmatics. The aim of this study was to characterize high- and low-dose allergen challenges in asthmatic patients using ICS. Twenty-eight asthmatic patients taking ICS (beclomethasone equivalent <1000 μg day(-1) ) were recruited for high-dose allergen challenge, of whom 10 subsequently also had a repeat low-dose challenge comprising seven allergen challenges. Induced sputum was collected for measurements of cell counts and supernatant biomarkers. The high-dose allergen challenge caused an early and late asthmatic response in 19 of 28 patients; the mean maximal fall in the forced expiratory volume in 1 s (FEV1 ) was 29.1% (SD 6.2%) and 25.1% (SD 9.6%), respectively. There was also an increase in sputum eosinophils of 6.2% (P = 0.0004), as well as supernatant eosinophil cationic protein levels. The low-dose allergen challenge caused an acute fall in FEV1 , but had no effect on FEV1 at 24 h after challenge or sputum measurements. The high-dose allergen challenge in asthmatics using ICS induces a late asthmatic response associated with an increase in eosinophilic airway inflammation. This may be a suitable model for studying the effects of novel anti-inflammatory drugs added to maintenance ICS treatment.

Evaluation of Inhalation Exposure to Carcinogenic PM10-Bound PAHs of People at Night Markets of an Urban Area in a Metropolis in Eastern China

Inhalable particle bounded carcinogenic polycyclic aromatic hydrocarbons (PAHs) pose high health risks to both food service workers and consumers cooking or purchasing late night snacks, respectively, in night markets because PAHs are generated in abundance during thermal cooking processes such as barbecue grilling. In the present study, sixteen carcinogenic PAHs in PM10 collected during open hours from eight night markets in an urban area of a metropolis in eastern China were determined. The total concentration of PAHs (ΣPAH) ranged from 145 to 1340 ng m–3, with an arithmetic mean of 828 ± 360 ng m–3. Five- and six-ringed PAHs were predominant in the composition, implying a combination of sources including cooking and traffic. Low coefficient of divergence values for individual PAH homologous among all sampling sites indicated similar sources. The occurrence of PM10-bound PAHs appeared to depend on the gas-particle partitioning processes and emission sources according to the results of principal component analysis (PCA). The daily inhalation rate of particle and predicted gaseous benzo[a]pyrene (BaP)-equivalent adjusted PAHs (BaPeq) for the workers due to occupational exposure was 0.451–3.43 µg day–1. Correspondingly, the occupational exposure risk for workers with one year of service was less than the acceptable risk level (10–6). However, the risk for people who had worked for more than 3 years exceeded 10–6 but was less than the priority risk level (10–4). For consumers, the maximum consumption time (tmax) for each time under the acceptable risk level would increase with an increase in age, and the exposure risk for infants, toddlers and children is high when PM10-bound PAHs are inhaled. We recommend that tmax should be less than 1 hour for consumers under 25 years old. Therefore, our results indicate that both workers and consumers in the night markets have high cancer risks due to inhalation of PM10-bound PAHs.

Selenium in soils under climate change, implication for human health

Global climate changes can alter the suitable geographical range of different crops, leading to possible changes in cropping pattern and its extent in some regions. For example, temperature changes can interact very closely with changes in availability of water and soil nutrients, and crop growth cycle. The consequences of the biophysical impacts of climate changes will be influenced by the human responses to these impacts. There is a strong link between soils and human health, and these soils per se are controlled by climate changes. The human health is very close to both selenium (Se) element and climate changes. It is estimated that about 37–40 % of the total Se emissions to the atmosphere are due to the anthropogenic activities. Those anthropogenic activities, which are sources of Se, include coal and oil combustion, mining activities, the utilization of rock phosphates as a fertilizer and the application of sewage sludge to agricultural land. It was thought that selenium was a toxicant for a long time due to inadequate analytical data. In the recent past, Se has become very important in environmental biogeochemistry because of its influence on human health. Although Se is an essential nutrient for animals and humans, it is also toxic at high doses. Furthermore, the range between Se deficiency, lower than 40 μg day−1, and toxicity, higher than 400 μg day−1, is narrow. Selenium deficiency has been linked to several human diseases including multiple sclerosis, muscular dystrophy, heart disease, immune system, cancer and reproductive disorders. On the other hand, Se toxicity can lead to hair and nail loss and disruption of the nervous and digestive systems in animals and humans. Despite the obvious connections between Se element and human health under climate changes, there has not been a great amount of research done in this area. So, more and more studies should be carried out to enhance and protect human health. Therefore, this article reviews the biological and economic dimensions of the effects of Se element on human health under climate changes.

Estimation of the intake of phenol compounds from virgin olive oil of a population from southern Spain

The objective of the study was to determine the mean polyphenol composition of different varieties of virgin olive oil (VOO) habitually consumed in the region of southern Spain and to estimate the dietary exposure to olive oil polyphenols in that population. There were statistically significant differences in total polyphenols among varieties, with the Picual variety containing the largest amount with a mean value of 591.8 mg kg–1. The main phenolic compounds found in the VOOs under study were tyrosol and hydroxytyrosol. The highest amounts of both substances were found in Picual olive oils with concentrations of 2.3–6.6 mg kg−1. The total intake of polyphenols from VOO ranged between 8.2 mg day–1 (SD = 4.14) for the under 19 year olds and 21.3 mg day–1 (SD = 3) for the over 50 year olds. Some polyphenols, including tyrosol and hydroxytyrosol, were consumed principally as olive oil. The intake of these compounds in the studied population was in the range of 88.5–237.4 μg day–1. This has particular importance as recent studies have demonstrated that hydroxytyrosol helps to improve plasma lipids levels and repair oxidative damage related to cardiovascular disease. There was a greater dietary consumption of polyphenols in olive oil among the participants who more closely followed the Mediterranean diet pattern. A higher consumption of olive oil and therefore a greater exposure to polyphenols was observed in females versus males and in participants of normal weight versus those who were overweight. The total intake of polyphenols from VOO significantly increased with higher age, reflecting the greater intake of this oil by older people, who also show a closer adherence to the Mediterranean diet. The over 50-year-old age group showed the greatest consumption of this olive oil and therefore of phenolic compounds, which are healthy protectors in the human diet that contribute to the acknowledged benefits of the Mediterranean diet.

Reductions in serum levels of LDL cholesterol, apolipoprotein B, triglycerides and lipoprotein(a) in hypercholesterolaemic patients treated with the liver-selective thyroid hormone receptor agonist eprotirome.

Liver-selective thyromimetic agents could provide a new approach for treating dyslipidaemia. We performed a multicentre, randomized, placebo-controlled, double-blind study to evaluate the efficacy and safety of eprotirome, a liver-selective thyroid hormone receptor agonist, in 98 patients with primary hypercholesterolaemia. After previous drug wash-out and dietary run-in, patients received 100 or 200 μg day(-1) eprotirome or placebo for 12 weeks. The primary end-point was change in serum LDL cholesterol; secondary end-points included changes in other lipid parameters and safety measures. Eprotirome treatment at 100 and 200 μg daily reduced serum LDL cholesterol levels by 23 ± 5% and 31 ± 4%, respectively, compared with 2 ± 6% for placebo (P < 0.0001). Similar reductions were seen in non-HDL cholesterol and apolipoprotein (apo) B, whereas serum levels of HDL cholesterol and apo A-I were unchanged. There were also considerable reductions in serum triglycerides and lipoprotein(a), in particular in patients with elevated levels at baseline. There was no evidence of adverse effects on heart or bone and no changes in serum thyrotropin or triiodothyronine, although the thyroxine level decreased. Low-grade increases in liver enzymes were evident in most patients. In hypercholesterolaemic patients, the liver-selective thyromimetic eprotirome decreased serum levels of atherogenic lipoproteins without signs of extra-hepatic side effects. Selective stimulation of hepatic thyroid hormone receptors may be an attractive way to modulate lipid metabolism in hyperlipidaemia.

Modeling flight attendants' exposures to pesticide in disinsected aircraft cabins.

Aircraft cabin disinsection is required by some countries to kill insects that may pose risks to public health and native ecological systems. A probabilistic model has been developed by considering the microenvironmental dynamics of the pesticide in conjunction with the activity patterns of flight attendants, to assess their exposures and risks to pesticide in disinsected aircraft cabins under three scenarios of pesticide application. Main processes considered in the model are microenvironmental transport and deposition, volatilization, and transfer of pesticide when passengers and flight attendants come in contact with the cabin surfaces. The simulated pesticide airborne mass concentration and surface mass loadings captured measured ranges reported in the literature. The medians (means ± standard devitions) of daily total exposure intakes were 0.24 (3.8 ± 10.0), 1.4 (4.2 ± 5.7), and 0.15 (2.1 ± 3.2) μg day(-1) kg(-1) of body weight for scenarios of residual application, preflight, and top-of-descent spraying, respectively. Exposure estimates were sensitive to parameters corresponding to pesticide deposition, body surface area and weight, surface-to-body transfer efficiencies, and efficiency of adherence to skin. Preflight spray posed 2.0 and 3.1 times higher pesticide exposure risk levels for flight attendants in disinsected aircraft cabins than top-of-descent spray and residual application, respectively.

Particulate matter analysis in indoor environments of urban and rural primary schools using passive sampling methodology

Passive sampling methodology was applied to collect particulate matter (PM) in classrooms of urban and rural primary schools. The samples were taken during a year by passive deposition allowing the study of seasonal variability of the particles masses and chemical content. Chemical characterization of the collected particles was performed in order to measure its soluble ions content and elemental composition. To identify the main polluting sources, correlations between parameters and enrichment factors were studied. Higher particle masses concentrations were registered in autumn, with a mean of 1.54 ± 0.74 μg day−1 cm−2. The major element in the collected particles was calcium, representing 63–73% of the analyzed mass of the particles inside the urban classrooms. In the rural cluster, calcium remained the major component but with a slight lower contribution to the overall particles composition (42–46%). The calcium source was hypothesized to be the chalk used in the blackboards of the classrooms due to a strong correlation found between Ca2+ and SO42−. Soil re-suspension, traffic and other anthropogenic emission sources were also identified. Analysis showed enrichment of the particles with Br, Ca, Zn and Sb in the urban cluster and enrichment of the same elements, except for Ca, in the rural cluster. The comparison between the results from both clusters allowed the identification of classrooms with higher particles concentrations that can indicate potential indoor air quality problems (reflected by an indoor accumulation of pollutants).

Gibberellic acid acts as an agonist of steroidogenesis in male rats

Testicular steroidogenesis has significant implication in male reproductive function. Although the effects of various signalling molecules on testicular functions have been studied earlier, the influence of the plant hormone gibberellic acid (GA3 ) on steroidogenesis has not been investigated. Acute (4 h) and subacute (15 days) studies using this compound through oral administration (150 μg day(-1) ) to groups of normal and diabetic Wistar male rats were therefore carried out. Results indicate that (i) enhanced activity of steroidogenic markers 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), elevated tissue testosterone (T) content, increased steroidogenic acute regulatory protein (StAR) and androgen binding protein (ABP) levels with reduced lipid peroxidation and improved antioxidant defence in this treatment group of normal and diabetic rat testis, and (ii) elevated lipid peroxidation and diminished antioxidant defence, with insignificant change in 3β-HSD and 17β-HSD activity and testosterone level in acute treatment group of normal and diabetic rats testis, were noted. The observed increase in the activity of testicular 3β-HSD and 17β-HSD along with elevated testosterone content established GA3 as an inducer of steroidogenesis in rat.

Children exposure assessment to ultrafine particles and black carbon: The role of transport and cooking activities

An accurate evaluation of the airborne particle dose–response relationship requires detailed measurements of the actual particle concentration levels that people are exposed to, in every microenvironment in which they reside.The aim of this work was to perform an exposure assessment of children in relation to two different aerosol species: ultrafine particles (UFPs) and black carbon (BC). To this purpose, personal exposure measurements, in terms of UFP and BC concentrations, were performed on 103 children aged 8–11 years (10.1 ± 1.1 years) using hand-held particle counters and aethalometers. Simultaneously, a time-activity diary and a portable GPS were used to determine the children's daily time-activity pattern and estimate their inhaled dose of UFPs and BC.The median concentration to which the study population was exposed was found to be comparable to the high levels typically detected in urban traffic microenvironments, in terms of both particle number (2.2 × 104 part. cm−3) and BC (3.8 μg m−3) concentrations. Daily inhaled doses were also found to be relatively high and were equal to 3.35 × 1011 part. day−1 and 3.92 × 101 μg day−1 for UFPs and BC, respectively.Cooking and using transportation were recognized as the main activities contributing to overall daily exposure, when normalized according to their corresponding time contribution for UFPs and BC, respectively. Therefore, UFPs and BC could represent tracers of children exposure to particulate pollution from indoor cooking activities and transportation microenvironments, respectively.