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In this study, the long-term transfer of 137Cs from soil to grass on Swedish farms and fields, heavily contaminated after the 1986 radioactive fallout, was investigated. The study spans over 8–14 years, beginning in June 1986, and covers various soil types and agricultural practices. The transfer of 137Cs from soil to grass was highly variable, with transfer factors ranging from 1.0 × 10−5 to 0.357 m2 kg−1. Higher values were observed on fields with sandy loam, loamy sand, and organic soils, and lower values on fields with a high clay content. The transfer of 137Cs to grass generally exhibited an exponential decline across the majority of fields over the years. The rate of decrease was most pronounced in clay loam and silty loam soils, while it was least evident in sandy loam, sandy soils, and peat soils. The soil properties and farming practices were more important for 137Cs uptake than the initial deposition density. The transfer factor had a negative correlation with soil pH, clay, and fine silt content. No significant relationships were found with other soil variables, such as soil organic matter content and plant available potassium concentration. The median effective half-life of 137Cs in the grass was 4.5 years, with a range of 2–18 years. The uptake of 137Cs by plants did not correlate with the potassium concentration in grass tissues; however, the activity concentration of 137Cs in grass correlated negatively with the potassium content in the plants grown on fields with high deposition levels. • Study explores long-term 137Cs transfer from soil to grass after Chernobyl fallout. • Transfer factors varied from 1.0 × 10−5 to 0.357 m2 kg−1, influenced by soil type. • Higher uptake rates found in sandy loam and loamy sand; lower in clay-rich soils. • Median effective half-life of 137Cs in grass was 4.5 years (2–18 years range). • 137Cs uptake by grass was negatively correlated with soil pH. [ABSTRACT FROM AUTHOR]

Outbreaks of acute gastrointestinal illnesses (AGI) have been linked to insufficient drinking water treatment on numerous occasions in the industrialized world, but it is largely unknown to what extent public drinking water influences the endemic level of AGI. This paper aimed to examine endemic AGI and the relationship with pathogen elimination efficacy in public drinking water treatment processes. For this reason, time series data of all telephone calls to the Swedish National Healthcare Guide between November 2007 and February 2014 from twenty Swedish cities were obtained. Calls concerning vomiting, diarrhea or abdominal pain (AGI calls) were separated from other concerns (non-AGI calls). Information on which type of microbial barriers each drinking water treatment plant in these cities have been used were obtained, together with the barriers’ theoretical pathogen log reduction efficacy. The total log reduction in the drinking water plants varied between 0.0 and 6.1 units for viruses, 0.0–14.6 units for bacteria and 0.0–7.3 units regarding protozoans. To achieve one general efficacy parameter for each plant, a weighted mean value of the log reductions (WLR) was calculated, with the weights based on how commonly these pathogen groups cause AGI. The WLR in the plants varied between 0.0 and 6.4 units. The effect of different pathogen elimination efficacy on levels of AGI calls relative non-AGI calls was evaluated in regression models, controlling for long term trends, population size, age distribution, and climatological area. Populations receiving drinking water produced with higher total log reduction was associated with a lower relative number of AGI calls. In overall, AGI calls decreased by 4% (OR = 0.96, CI: 0.96–0.97) for each unit increase in the WLR. The findings apply to both groundwater and surface water study sites, but are particularly evident among surface water sites during seasons when viruses are the main cause of AGI. This study proposes that the endemic level of gastroenteritis can indeed be reduced with more advanced treatment processes at many municipal drinking water treatment plants. [ABSTRACT FROM AUTHOR]

• Improved efficiency in drinking water treatment may reduce gastrointestinal illness. • SMS is a data collection tool that is easy to use, with a high response rate. • Reduced gastrointestinal illness was observed among children, but not in adults. There are indications that drinking water may contribute to endemic gastrointestinal illness (GII) even when the drinking water quality meets current standards, but the knowledge is limited. In this population-based prospective study, we assessed if changes in municipal drinking water production affected the GII incidence, by collecting self-reported GII episodes among the population in two municipalities during calendar time-specific inter-annual periods. About 2600 adults in central Sweden and 2600 adults (including 700 households with children aged 0–9 years) in Southwest Sweden, were followed during a baseline and a follow-up period in 2012–2016. Monthly reports of episodes and symptoms of GII were collected by SMS. The following drinking water related changes were assessed: Change 1 (adults) ; a municipality with a groundwater treatment, changed to a different groundwater source with UV treatment; Change 2 (adults) ; a municipality with a surface water treatment changed to a groundwater source with UV treatment; and Change 3a (adults) and 3b (children): a municipality with a surface water treatment changed to a new surface water source, having a treatment with a higher pathogen reduction. We observed no evidence that changes in raw water source and/or improved pathogen removal in the drinking water treatment affected the risk of GII among adults. Among children aged 0–9 years participating in Change 3b, we observed a 24% relative risk reduction in GII incidence. These results suggest that improved water treatment may reduce the disease burden of GII in children even in settings in which water treatment efficacy meets current quality standards. [ABSTRACT FROM AUTHOR]

During recent years, knowledge gaps on drinking water-related gastrointestinal illness have been identified, especially for non-epidemic cases. Pathogen contamination of drinking water during distribution has been suggested to contribute to these cases, but the risk factors are not yet fully understood. During 2014–2015, we conducted an epidemiological study in five municipalities in Sweden, to assess whether incidents in the drinking water distribution system influence the risk of gastrointestinal illness. Telephone interviews were conducted in the affected areas and in reference areas 7–14 days after a reported incident. Symptoms of gastrointestinal illness occurring during the period were documented for each household member. The results showed a significantly elevated risk of vomiting and acute gastrointestinal illness (AGI) in the affected areas, compared to the reference areas (OR vom. = 2.0, 95% CI: 1.2–3.3; OR AGI = 1.9, 95% CI: 1.2–3.0). Certain conditions, or risk factors, during the incidents, such as sewage and drinking water pipelines at the same level in the trench, were associated with an elevated risk of AGI and vomiting. Safety measures taken during repair work, like flushing, were also associated with an elevated risk of AGI and vomiting. These results show that incidents in the drinking water distribution network contribute to endemic gastrointestinal illness, especially AGI and vomiting, and that external pathogen contamination of the drinking water is a likely cause of these cases of gastrointestinal illness. The results also indicate that safety measures used today may not be sufficient for eliminating the risk of gastrointestinal illness. [ABSTRACT FROM AUTHOR]

• P and S speciation in particles leached through four agricultural lands were studied. • Si, Al, K, Mg, Ca, and Fe were the most abundant elements in the leached particles. • Multi-elemental co-localizations shows P to be localized mostly with S and Al. • S K- edge XANES shows S in the leached particles to be mainly organic S. • P K- edge XANES confirmed P to exist as organic P and as P adsorbed to Al surfaces. Colloids and nanoparticles leached from agricultural land are major carriers of potentially bioavailable nutrients with high mobility in the environment. Despite significant research efforts, accurate knowledge of macronutrients in colloids and nanoparticles is limited. We used multi-elemental synchrotron X-ray fluorescence (XRF) microscopy with multivariate spatial analysis and X-ray atomic absorption near-edge structure (XANES) spectroscopy at the P and S K -edges, to study the speciation of P and S in two fractions of leached particles, >0.45 and <0.45 µm respectively, collected from four tile-drained agricultural sites in Sweden. P K -edge XANES showed that organic P, followed by P adsorbed to surfaces of aluminum-bearing particles were the most common forms of leached P. Iron-bound P (Fe-P) forms were generally less abundant (0–30 % of the total P). S K -edge XANES showed that S was predominantly organic, and a relatively high abundance of reduced S species suggests that redox conditions were adverse to the persistence of P bound to Fe-bearing colloids in the leachates. Acid ammonium-oxalate extractions suggested that P associated with Al and Fe (Al-P and Fe-P) in most cases could be explained by the adsorption capacity of non-crystalline (oxalate-extractable) oxides of Al and Fe. These results improve our understanding of particulate P and S speciation in the vadose zone and helps in developing effective technologies for mitigating colloidal driven eutrophication of water bodies near agricultural land. Image, graphical abstract [ABSTRACT FROM AUTHOR]