Concentrations Of Agrochemicals Research Articles

Agrochemical inputs to managed oil palm plantations are a probable risk to ecosystems: Results from a screening level risk assessment

Palm oil is a high value crop widely grown in the tropics. The management of palm oil is characterised by widespread agrochemical use. Here we report the results of a screening level risk assessment conducted from the available literature on the environmental concentration of agrochemicals in surface waters and soils in palm oil growing areas. To date, only a small number of published studies have measured pollutant concentrations in and around palm oil plantations. To identify potential high-risk contaminants, a standard SSD based risk assessment, establishing risk quotients for detected contaminants, was conducted in relation to available species sensitivity distributions. A probabilistic SSD based risk assessment, calculating potential risk distributions, was also conducted for contaminants with the required number of data points available. Metals were the most commonly detected (and measured) substances and also presented the greatest risk, especially copper and zinc, but also nickel, lead and cadmium. For these metals, environmental concentrations overlapped levels found to cause effects in toxicity studies, indicating the potential for adverse outcomes from exposure. To fully understand the extent of this risk, more detailed studies are needed that assess metal speciation states and bioavailability under the prevailing soil and water chemistry conditions in palm oil plots. Limited studies have measured pesticide concentrations in palm oil systems. In these few cases, only a few active substances have been measured. From the limited information available, potential risks are indicated due to the presence of some insecticides. However, fungicides are also widely used for palm oil disease management, but little data studies are available to assess both exposure and potential effects. To further assess the potential chemical footprint of different palm oil management practices, studies are needed that systematically assess pollutant levels across a range of chemical groups to consider effects within a mixture context.

Use of lichens as bioindicators of contamination by agrochemicals and metals.

The presence or absence of lichens serves as an indicator of the condition of an ecosystem and the degree to which it is contaminated by various agents, such as agrochemicals and metals. Evaluating the use of lichens as bioindicators of agrochemical contamination could provide a more comprehensive perspective of current contamination levels. Monitoring was conducted over a 4-month period in two study areas: one was a well-conserved area contaminated by metals, and the other was an area surrounded by agricultural crops contaminated by agrochemicals. Data on the presence and abundance of lichens in each study area were recorded at 10 monitoring points, a procedure that was repeated 16 times (every 15days), and concentrations of heavy metals and "organophosphate" agrochemicals in the lichens collected were measured by means of Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES) and Gas Chromatography (GC), respectively. Generalized linear mixed models were used to assess abundance and richness, while general linear mixed models were used to attain Shannon diversity and Simpson dominance indices. Moreover, a multivariate analysis was performed in order to compare the lichen communities in both areas. The results indicated differences between the area contaminated by metals and that contaminated by agrochemicals in terms of abundance and Simpson's dominance index, while no differences were found in the case of the richness and diversity models. The PERMANOVA analysis additionally showed differences between the lichen communities in the two areas. The results also demonstrated that Canoparmelia caroliniana bioaccumulated metals in both areas. The levels of barium, cadmium, and sodium were higher in the area contaminated by metals, while concentrations of chromium and copper were higher in the area contaminated by agrochemicals. Finally, the concentrations of agrochemicals were higher in the area contaminated by agrochemicals and included toxic substances such as Methylparathion and Parathion, which are prohibited in Ecuador. In conclusion, this research underscores the importance of lichens as precise indicators of environmental health and contamination by agrochemicals and metals.

Combined effects of landscape composition and agrochemicals on frog communities amid sugarcane-dominated agroecosystems.

Global demand for crops will continue increasing over the next few decades to cover both food and biofuel needs. This demand will put further pressure to expand arable land and replace natural habitats. However, we are only beginning to understand the combined effects of agrochemicals and land-use change on tropical freshwater biodiversity. In this study, we analyzed how pond-dwelling anuran larvae responded to pond characteristics, landscape composition, and agrochemical contamination in a sugarcane-dominated agroecosystem in Brazil. Then we used an information theoretical approach with generalized linear models to relate species richness and abundance to predictor variables. The variation in tadpole abundance was associated with both agrochemical concentration (e.g., ametryn, diuron, and malathion) and landscape variables (e.g., percentage of forest, percentage of agriculture, and distance to closest forest). The relationship between species abundance and agrochemicals was species-specific. For example, the abundances of Scinax fuscovarius and Physalaemus nattereri were negatively associated with ametryn, and Dendropsophus nanus was negatively associated with tebuthiuron, whereas that of Leptodactylus fuscus was positively associated with malathion. Conversely, species richness was associated with distance to forest fragments and aquatic vegetation heterogeneity, but not agrochemicals. Although we were unable to assign a specific mechanism to the variation in tadpole abundance based on field observations, the lower abundance of three species in ponds with high concentrations of agrochemicals suggest they negatively impact some frog species inhabiting agroecosystems. We recommend conserving ponds near forest fragments, with abundant stratified vegetation, and far from agrochemical runoffs to safeguard more sensitive pond-breeding species.

On using lumped-parameter models in groundwater protection zones to predict aquifer response to reduced agrochemical input

• Waiting times for aquifers contaminated by agrochemicals are useful for management. • Lumped-parameter models can be used to estimate these waiting times. • Waiting times useful for management must not be confused with mean transit times. In groundwater protection zones, water managers and water providers will typically need to know the time scale of recovery for aquifers contaminated by agrochemicals. Despite the large body of work on the topic in the scientific literature, there still seems to be some need to clarify which waiting times are most relevant for water management planning, and how they relate to metrics such as the mean transit time of tracer. Firstly, we propose a simple nomenclature for the different waiting times and how they relate to the evolution of agrochemical concentration (increasing and decreasing concentration trends, trend reversal, etc.). Secondly, we describe how to select and fit a lumped-parameter model to contaminant time series and environmental isotopes in order to characterize aquifer response to agrochemical contamination. Thirdly, we explain how waiting times can be calculated from the fitted lumped-parameter model. Finally, we present a case study focussing on the contamination of several springs of the city of Luxembourg by a fungicide transformation product combining environmental tracers and pesticide measurements. We find that on the study site, the parameters estimated separately from the environmental tracers and from the pesticide data are nearly the same although they correspond to different areas within the groundwatershed. Although this could be incidental, it might also indicate that robust waiting time estimates can be obtained from agrochemical time series and environmental tracer measurements, at least in simple cases.

Pesticide dynamics in agroecosystems: Assessing climatic and hydro-physical effects in a soybean cycle under no-tillage

The high rate of No-Tillage (NT) adoption in Argentina has been followed by conspicuous application of herbicides due to RR crops selection and recently due to weed resistance. In addition, no-tillage in the Rolling Pampa (Argentina) with absence of crop rotation and scarce crop residues, led to physical degradation (low infiltration rates, platy structure development) having strong implications on water dynamics and the risk of soil and water contamination. Several factors can influence the mobility of pesticides in the landscape. However, measurement of soil hydro-physical and climate traits as determinants of pesticide dynamics are still scarce. In this study, pesticides from soil and runoff (Glyphosate, AMPA, S-Metolachlor, Sulfentrazone), and hydro-physical and climatic variables were measured at the field in an entire soybean cycle under NT. Temporal dynamics of runoff and saturated hydraulic conductivity was measured by rainfall simulations and disc permeameters together with soil bulk density, soil moisture, crop residues, rainfall and rainfall erosivity. Besides, soil structure was evaluated through cultural profile method. In the Vertic Argiudoll (silty clay loam) pesticides mobility were related to the number of days after agrochemical application modulated also by heavy natural rainfalls occurred during the experiment that lowered agrochemical concentration mostly in runoff. Temporal hydro-physical properties and spatial soil structural variability, together with strong climatic events governed runoff process affecting pesticides mobility while no strong pesticide accumulation in the plots was observed in this study due to low saturated hydraulic conductivity, high runoff coefficients and poor soil structural traits. Thus, the selection of appropriate agricultural management is a key factor to modify hydro-physical top soil dynamics to change hydrological partition from horizontal to vertical fluxes, in particular in soils with poor structural condition.

Effects of agrochemical pollution on schistosomiasis transmission: a systematic review and modelling analysis

BackgroundAgrochemical pollution of surface waters is a growing global environmental challenge, especially in areas where agriculture is rapidly expanding and intensifying. Agrochemicals might affect schistosomiasis transmission through direct and indirect effects on Schistosoma parasites, their intermediate snail hosts, snail predators, and snail algal resources. We aimed to review and summarise the effects of these agrochemicals on schistosomiasis transmission dynamics.MethodsWe did a systematic review of agrochemical effects on the lifecycle of Schistosoma spp and fitted dose-response models to data regarding the association between components of the lifecycle and agrochemical concentrations. We incorporated these dose-response functions and environmentally relevant concentrations of agrochemicals into a mathematical model to estimate agrochemical effects on schistosomiasis transmission. Dose-response functions were used to estimate individual agrochemical effects on estimates of the agrochemically influenced basic reproduction number, R0, for Schistosoma haematobium. We incorporated time series of environmentally relevant agrochemical concentrations into the model and simulated mass drug administration control efforts in the presence of agrochemicals.FindingsWe derived 120 dose-response functions describing the effects of agrochemicals on schistosome lifecycle components. The median estimate of the basic reproduction number under agrochemical-free conditions, was 1·65 (IQR 1·47–1·79). Agrochemical effects on estimates of R0 for S haematobium ranged from a median three-times increase (R0 5·05, IQR 4·06–5·97) to transmission elimination (R0 0). Simulations of transmission dynamics subject to interacting annual mass drug administration and agrochemical pollution yielded a median estimate of 64·82 disability-adjusted life-years (DALYs) lost per 100,000 people per year (IQR 62·52–67·68) attributable to atrazine use. In areas where aquatic arthropod predators of intermediate host snails suppress transmission, the insecticides chlorpyrifos (6·82 DALYs lost per 100,000 people per year, IQR 4·13–8·69) and profenofos (103·06 DALYs lost per 100,000 people per year, IQR 89·63–104·90) might also increase the disability burden through their toxic effects on arthropods.InterpretationExpected environmental concentrations of agrochemicals alter schistosomiasis transmission through direct and indirect effects on intermediate host and parasite densities. As industrial agricultural practices expand in areas where schistosomiasis is endemic, strategies to prevent increases in transmission due to agrochemical pollution should be developed and pursued.

Removal of Agrochemicals from Waters by Adsorption: A Critical Comparison among Humic-Like Substances, Zeolites, Porous Oxides, and Magnetic Nanocomposites

The use of humic-like substances, zeolites, various porous oxides (i.e., Al, Fe, or Si oxides), and magnetic nanocomposites in the adsorption of agrochemicals from water was critically reviewed. Firstly, the adsorbents were characterized from the structural, textural, and physico-chemical points of view. Secondly, the fundamental aspects of the adsorption of various agrochemicals on the solids (dependence on pH, kinetics, and isotherm of adsorption) were studied and interpreted on the basis of the adsorbent features. Thirdly, iterative processes of agrochemical removal from water by adsorption on the reported solids were described. In particular, in some cases the residual concentration of agrochemicals in water was lower than the maximum concentration of agrochemicals that the Italian regulations allow to be released in wastewater, surface waters, or sink water.

Setal anomalies in the tropical earthworms Drawida willsi and Lampito mauritii exposed to elevated concentrations of certain agrochemicals: An electron micrographic and molecular docking approach

Abstract Setae are the functional organelle in the earthworms which act as anchors and thus are crucial for locomotion. Structural anomaly or loss of setae could result in significant functional loss in these animals. The present study reports novel observation on setal anomalies in two tropical earthworms, Drawida willsi and Lampito mauritii exposed to elevated concentrations of the agrochemicals, monocrotophos, glyphosate, urea, phosphogypsum (PG) and paper mill sludge (PMS) in soil. Three concentrations of monocrotophos (1.0, 2.0, 3.0 g/kg soil), glyphosate (0.1, 0.15, 0.2 g/kg soil), urea (0.5, 1.0, 1.5 g/kg soil), PG (50, 100, 150 g/kg soil) and PMS (5, 10, 15 g/kg soil) were used as per recommended agricultural doses and the animals were exposed for 24 h in treated soils to observe their effects on the setae. Scanning electron microscopic images revealed various setal structural deformities in both the worms. Urea had the maximum deleterious impact relative to other test chemicals. Computational analysis indicated that the high binding affinity of urea with the chitin of setae was responsible for the maximum conformational changes in the later. Setal anomalies could be used as early signal markers to evaluate soil toxicity.

Effects of Agrochemical Pollution on Schistosomiasis Transmission: A Systematic Review and Modeling Analysis

Background: Agrochemical pollution of surface waters is a growing global environmental challenge, especially in areas where agriculture is rapidly expanding and intensifying. Recent work suggests that agrochemicals may affect schistosomiasis transmission through direct and indirect effects on Schistosoma parasites, their intermediate snail hosts, snail predators, and snail algal resources. Methods: We conducted a systematic review of agrochemical effects on the lifecycle of Schistosoma spp. and fitted dose-response models to data relating components of the lifecycle and agrochemical concentrations. We incorporated these dose-response functions and environmentally-relevant concentrations of agrochemicals into a mathematical model to estimate agrochemical effects on schistosomiasis transmission. Findings: We derived 120 dose-response functions describing effects of agrochemicals on schistosome lifecycle components. Agrochemical effects on estimates of the basic reproduction number, R0, for S. haematobium ranged from an increase of 306% (IQR: 246% – 362%) to transmission elimination (R0 -> 0). Simulations of transmission dynamics subject to interacting annual mass drug administration and agrochemical pollution yield a median estimate of 64·82 (IQR: 62·52 – 67·68) DALYs lost per 100,000 people per year attributable to atrazine use. In areas where aquatic arthropod predators of intermediate host snails suppress transmission, the insecticides chlorpyrifos and profenofos may also increase disability (6·82 [4·13 – 8·69] and 103·06 [89·63 – 104·90] DALYs lost per 100,000 people per year, respectively) through their toxic effects to arthropods. Interpretation: Expected environmental concentrations of agrochemicals alter schistosomiasis transmission through direct and indirect effects on intermediate host and parasite densities. As industrial agricultural practices expand in areas where schistosomiasis is endemic, strategies to limit increases in transmission due to agrochemical pollution should be developed and pursued. Funding Statement: Funding from the National Institutes of Health [1R01TW010286 and R01AI125842], the National Science Foundation Water, Sustainability and Climate program [1360330 and 1646708] and DS421 training program [1450053], and by the University of California Multicampus Research Programs and Initiatives [award MRP-17-446315]. Declaration of Interests: The authors report no competing interests.

Pesticides and antibiotics in permanent rice, alternating rice-shrimp and permanent shrimp systems of the coastal Mekong Delta, Vietnam

BackgroundSalinity intrusion into coastal regions is an increasing threat to agricultural production of salt sensitive crops like paddy rice. In the coastal Mekong Delta, farmers respond by shifting to more salinity tolerant agricultural production systems such as alternating rice-shrimp and permanent shrimp. While shrimps are sensitive to pesticide residues used on rice, the use of antibiotics in shrimp farming can cause contamination in rice crops. These patterns of cross-contamination are not well documented empirically in the rapidly changing agricultural landscape. Objective and methodsOur objective was to understand changing pollution patterns induced by shifts in agricultural land use system. We addressed this by i) documenting pesticide and antibiotic use in three different agriculture land use systems (permanent rice, alternating rice-shrimp and permanent shrimp), and by ii) determining residues of pesticides and antibiotics in top soil layers of these three land use systems. Samples were taken in Sóc Trăng and Bến Tre province in the Mekong Delta, Vietnam. Chemical analyses comprised 12 of the most commonly used pesticides in rice paddies and six common antibiotics used in shrimp production. ResultsResults showed that residues of pesticides were present in all agricultural land use systems, including shrimp aquaculture. Active ingredients were mostly fungicides with a maximum concentration of 67 μg kg−1 found for isoprothiolane in permanent rice systems, followed by alternating rice-shrimp and permanent shrimp systems. Furthermore, antibiotics were present ubiquitously, with fluoroquinolones accumulating to larger amounts than sulfonamides and diaminopyrimidines. All concentrations were below critical lethal threshold values. ConclusionOverall, farmers were most conscious of agrochemical use in alternating rice-shrimp systems to prevent harm to shrimps, which was reflected in overall lower concentrations of agrochemicals when compared to rice systems. Thus, alternating rice-shrimp systems present a low risk option in terms of food safety, which may bring additional benefits to this so far rather low-input system in brackish water transition zone.

Novel process to prepare magnetic metal-ceramic nanocomposites from zeolite precursor and their use as adsorbent of agrochemicals from water

In this work the preparation of two samples of magnetic adsorbent from a zeolite precursor was described. This process implied NH4+ and Fe2+ exchange of zeolite A and its subsequent thermal treatment at temperature 600–800 °C, under a reducing atmosphere. These two magnetic adsorbents, composed of Fe/Fe3O4 nanoparticles embedded in an amorphous silica-alumina ceramic phase, were fully characterized by determining their chemical composition, quantitative phase analysis, surface area, SEM and TEM analysis, pH of zero potential and magnetic properties. In particular, their Fe content was 0.2 or 4.8%, Fe3O4content 5.4 or 7.1% and the average dimension of nanoparticles was 1.82 or 11.13 nm. Then, the removal of the agrochemical simazine from water was performed by using these two magnetic adsorbents. The investigated parameters were pH, time, solid/liquid ratio and initial simazine concentration. The pH of maximum simazine adsorption was 6.5 and 3.0 for the two adsorbents. At these pH values, simazine adsorption occurred rapidly and massively even from very dilute simazine solutions (simazine concentration of about 0.25 μmole/L).Finally, a process of simazine removal from waters based on repeated cycles of adsorbent addition to simazine bearing water, followed by its easy magnetic separation, is proposed. This process allows bringing the final agrochemical concentration well below 0.05 mg/L, the maximum agrochemical concentration allowed by Italian laws in wastewaters. Simazine bearing exhausted adsorbents are regenerated by a (no more than) 5 min thermal treatment at 300 °C, which results in the decomposition of simazine without damage of the adsorbent.

Internal hive temperature as a means of monitoring honey bee colony health in a migratory beekeeping operation before and during winter

Internal temperatures of honey bee hives kept at different sites in North Dakota were monitored before and during winter to evaluate the effects of treatment, in the form of exposure to commercial pollination, and location on colony health. In October, hives exposed to commercial pollination during the summer had fewer adult bees and less brood than hives kept near natural forage, as well as lower average temperatures throughout winter. Within-day temperature variability was higher among hives exposed to commercial agriculture than for those kept near natural forage, indicating reduced temperature control. Fungicides, insecticides, varroacides, and an herbicide were detected in bee bread and wax samples; no major differences were observed either in the diversity or in the concentrations of agrochemicals with the exception of chlorpyrifos at one site. Varroa and Nosema densities were low overall. Data from the same site used in successive years showed significantly more brood the first year, as well as lower temperature variability; high levels of chlorpyrifos were detected in bee bread of colonies in the second year. Colony average temperature and temperature variability were informative with respect to colony phenology and post-winter status.

Combined Effects of Pesticides and Trematode Infections on Hourglass Tree Frog Polypedates cruciger.

The impact of widespread and common environmental factors, such as chemical contaminants, on infectious disease risk in amphibians is particularly important because both chemical contaminants and infectious disease have been implicated in worldwide amphibian declines. Here we report on the lone and combined effects of exposure to parasitic cercariae (larval stage) of the digenetic trematode, Acanthostomum burminis, and four commonly used pesticides (insecticides: chlorpyrifos, dimethoate; herbicides: glyphosate, propanil) at ecologically relevant concentrations on the survival, growth, and development of the common hourglass tree frog, Polypedates cruciger Blyth1852. There was no evidence of any pesticide-induced mortality on cercariae because all the cercariae successfully penetrated each tadpole host regardless of pesticide treatment. In isolation, both cercarial and pesticide exposure significantly decreased frog survival, development, and growth, and increased developmental malformations, such as scoliosis, kyphosis, and also edema and skin ulcers. The combination of cercariae and pesticides generally posed greater risk to frogs than either factor alone by decreasing survival or growth or increasing time to metamorphosis or malformations. The exception was that lone exposure to chlorpyrifos had higher mortality without than with cercariae. Consistent with mathematical models that suggest that stress should increase the impact of generalist parasites, the weight of the evidence from the field and laboratory suggests that ecologically relevant concentrations of agrochemicals generally increase the threat that trematodes pose to amphibians, highlighting the importance of elucidating interactions between anthropogenic activities and infectious disease in taxa of conservation concern.

A modeling approach for agricultural water management in citrus orchards: cost-effective irrigation scheduling and agrochemical transport simulation.

The water flow and the mass transport of agrochemicals in the unsaturated and saturated zone were simulated in the extended alluvial basin of Keritis river in Crete, Greece (a predominantly flat and most productive citrus growing area) using the hydrological model MIKE SHE. This model was set up based on information on land use, geology, soil structure, meteorological data, as well as groundwater level data from pumping wells. Additionally, field measurements of the soil moisture at six different locations from three soil depths (0.1, 0.2, and 0.3 m) were used as targets to calibrate and validate the unsaturated flow model while for saturated condition, groundwater level data from three well locations were used. Following the modeling approach, the agrochemical mass transport simulation was performed as well, based on different application doses. After the successful calibration processes, the obtained 1D modeling results of soil moisture-pressure related to soil depth at different locations were used to design a proper and cost-effective irrigation programme (irrigation timing, frequency, application rates, etc.) for citrus orchards. The results of the present simulation showed a very good correlation with the field measurements. Based on these results, a proper irrigation plan can be designed at every site of the model domain reducing the water consumption up to 38% with respect to the common irrigation practices and ensuring the citrus water productivity. In addition, the effect of the proposed irrigation scheduling on citrus yield was investigated. Regarding the agrochemical concentration in the groundwater for all dose cases was below the maximum permissible limit. The only exception was for the highest dose in areas where the water table is high. Thus, this modeling approach could be used as a tool for appropriate water management in an agricultural area estimating at each time and location the availability of soil water, contributing to a cost-effective irrigation plan.

Screening breeding sites of the common toad (Bufo bufo) in England and Wales for evidence of endocrine disrupting activity

Anuran amphibians are often present in agricultural landscapes and may therefore be exposed to chemicals in surface waters used for breeding. We used passive accumulation devices (SPMD and POCIS) to sample contaminants from nine breeding sites of the Common toad (Bufo bufo) across England and Wales, measuring endocrine activity of the extracts in a recombinant yeast androgen screen (YAS) and yeast estrogen screen (YES) and an in vitro vitellogenin induction screen in primary culture of Xenopus laevis hepatocytes. We also assessed hatching, growth, survival, and development in caged larvae in situ, and sampled metamorphs for gonadal histopathology. None of the SPMD extracts exhibited estrogen receptor or androgen receptor agonist activity, while POCIS extracts from two sites in west-central England exhibited concentration-dependent androgenic activity in the YAS. Three sites exhibited significant estrogenic activity in both the YES and the Xenopus hepatocyte. Hatching rates varied widely among sites, but there was no consistent correlation between hatching rate and intensity of agricultural activity, predicted concentrations of agrochemicals, or endocrine activity measured in YES/YAS assays. While a small number of intersex individuals were observed, their incidence could not be associated with predicted pesticide exposure or endocrine activitity measured in the in vitro screens. There were no significant differences in sex ratio, as determined by gonadal histomorphology among the study sites, and no significant correlation was observed between proportion of males and predicted exposure to agrochemicals. However, a negative correlation did become apparent in later sampling periods between proportion of males and estrogenic activity of the POCIS sample, as measured in the YES. Our results suggest that larval and adult amphibians may be exposed to endocrine disrupting chemicals in breeding ponds, albeit at low concentrations, and that chemical contaminants other than plant protection products may contribute to endocrine activity of surface waters in the agricultural landscape.

Occurrence of agrochemicals in surface waters of shallow soils and steep slopes cropped to tobacco

Tobacco cultivation in shallow soils and steep landscape under intense use of agrochemicals contributes to environment degradation. In this study, we assessed the concentration of agrochemicals in draw wells used for human consumption and a creek in a small catchment predominantly cropped to tobacco. Chlorpyrifos, flumetralin, and iprodione were determined by gas chromatography with electron capture detection, while imidalcloprid, atrazine, simazine, and clomazone were quantified by high-performance liquid chromatography with UV detection. Considering all sampling sites, all agrochemicals were detected at least once, except for flumetralin. The occurrence of agrochemicals in tobacco crops is a consequence of their fast transfer to surface water.

Cyclic process of simazine removal from waters by adsorption on zeolite H-Y and its regeneration by thermal treatment

Removal of the agrochemical simazine from polluted waters through adsorption by zeolite Y in its protonic form was studied. The investigated parameters were: pH, time, initial simazine concentration and solid/liquid ratio. An iterative process of simazine removal from waters is proposed, featuring: (i) final agrochemical concentration well below 0.05mg/dm3, the maximum concentration allowed by Italian laws in wastewaters; (ii) regeneration of the adsorbent by a few minutes thermal treatment in air at about 500°C, which results in the combustion of simazine without damage of the adsorbent; (iii) destruction of the agrochemical compound by combustion.

Agrochemical Concentration Level in Zaria Dam Reservoir and Ground Waters in the Environs

This study examines the effect of agrochemical used for faming in the Galma Dam area on the quality of water in the reservoir and well water around the reservoir. Nine sampling points upstream of the Galma Dam were randomly se- lected for the study. Also, six hand dug wells in use by adjacent communities were identified for ground water samples. The study covered the period July to September 2011. All measurements were in accordance with the Standard Methods for the Examination of Water and Wastewater. The parameters measured and their mean concentrations from the reser- voir are in the order of: Chlorides (0.600 - 0.900 mg/l); Nitrates (0.009 - 0.019 mg/l); Bicarbonates; 0.444 - 1.900 mg/l); Total Phosphates (0.173 - 3.077 mg/l); Sulphates (0.617 - 3.587 mg/l); and pH (6.4 - 7.5). For the well water samples, the results ranged from 1.58 - 3.10 mg/l; 0.14 - 0.03 mg/l; 0.60 - 2.73 mg/l; 0.08 - 1.89 mg/l; 0.33 - 2.66 mg/l and 6.05 - 7.0 respectively in the order previously listed. The results were statistically analyzed using ANOVA at 95% confidence level. Chlorides showed no significant variation between sampling points but significant variation with dates of sam- pling for surface and well waters. Nitrates variations with both sampling points and dates of sampling were insignificant. Bicarbonates variations with sampling points and dates of sampling were highly significant. Total Phosphates and Sul- phates variations with sampling points and dates of sampling were insignificant and significant respectively. pH values variations with sampling points and dates of sampling were insignificant and highly significant respectively. Generally, the mean concentrations are within the WHO maximum limits of the parameters in drinking water and recommenda- tions were made regarding the use of agrochemicals for farming in the area.

The effect of agrochemicals on indicator bacteria densities in outdoor mesocosms

Water bodies, which are monitored for microbial water quality by quantification of faecal indicator organisms (IOs), can contain various zoonotic pathogens contributed by livestock waste and other sources. Sediments can serve as reservoirs of IOs and other enteric microorganisms, including pathogens. Agrochemicals may influence the survival of these microorganisms in water bodies impacted by livestock waste by enhancing or reducing their survival. Complex, 1100 l, freshwater mesocosms containing leaf litter, zooplankton, periphyton, phytoplankton, and invertebrate and vertebrate animals were used to investigate the response of Escherichia coli and enterococci to agrochemicals. Replicate tanks were treated with atrazine, malathion, chlorothalonil and inorganic fertilizer, either alone at 1× or 2× their expected environmental concentrations (EECs) or in pair-wise combinations at their EECs. IOs inoculated in sediment (∼10⁴ cfu per 100 ml) were enumerated over 28 days. IOs generally declined over time, but manova revealed that addition of fertilizer and atrazine resulted in significantly greater IO densities. Malathion, chlorothalonil and agrochemical concentration (1× vs 2×) did not significantly affect IO densities and no significant interactions between agrochemicals were noted. The augmentation of IO densities in sediments by fertilizer and atrazine may impact their reliability as accurate predictors of water quality and human health risk, and indicates the need for a better understanding of the fate of IOs and enteric pathogens in sediments exposed to agrochemicals.

Highlights in this issue

Birth defects were found to be more common in American infants conceived between April and July. This has been related to the finding of higher concentrations of pesticides, particularly agrochemicals in surface water. 11 of 22 birth defects were more likely to occur if conceived during the season when the concentration of agrochemicals were highest. See article by Paul D. Winchester et al. (pp. 664-669). Small infants lack object permanence i.e. if an object is removed out of sight, the infant is not aware of it (out of mind). By measuring object permanence as an indicator of early working memory, Jean Lowe et al. found that toddlers born very low birth weight were less likely to demonstrate attainment of object permanence. These difficulties can persist throughout childhood and lead to learning difficulties (pp. 660-663). About 200 000 children die every year due to measles. Hamidah Hussain et al describe the endemic measles in Karachi, Pakistan. Although the vaccination coverage has increased considerably, vaccination campaigns are necessary to exceed 90% coverage (pp. 720-724). See also article by Sven Arne Silfverdal et al. demonstrating that breastfeeding may cause a modest reduced risk for clinical measles up to the age of 10 years (pp. 715-719). About 25% of the world population is at risk of zinc deficiency. Yasemin Üçkardeş et al report that zinc supplementation can significantly decrease the risk of attention deficit and hyperactivity. Zinc is also an important element in the preservation of immune resistance. Children with moderate bronchial asthma benefit from a diet supplementation with zinc, omega-3 fatty acids and vitamin C (pp. 731-736). See also article by Mohammed AL Biltagi et al. (pp. 737-742). Electrical injuries should be preventable. However, William Dokov report from Bulgaria an average of nearly 25 deaths per year in children due to electrocution. Most of these were due to domestic incidents. Some cases were due to attempts to steal live electrical conduits (pp. 756-757). This year's Swedish award is given to Anna-Karin Edstedt Bonamy, who has published an article together with Johan Bengtsson, Zoltan Nagy, Hans De Keyzer and Mikael Norman entitled ‘Preterm birth and maternal smoking in pregnancy are strong risk factors for aortic narrowing in adolescence’. Subjects born preterm were found to have about 15-20% narrowing of the aortic lumen. It may explain why these children may have a higher risk of developing hypertension later in life (Acta Paediatr 2008; 97:1080-5).