[Nitrate concentrations in tap water in Spain]

[Depressive symptoms in a sample of women with subclinical hypothyroidism and their relationship to chlorates in tap water]

INTRODUCTION

depressive symptoms may develop in subclinical hypothyroidism and their presence usually facilitates recognition and the establishment of replacement treatment; however, recent studies have found no association between the two. Be-sides, thyroid function can be affected by endocrine disruptors and some of them, such as chlorates, can be found in the water we drink.

OBJECTIVES

to know if the type of water consumed may influence the development of depressive symptoms in patients with subclinical hypothyroidism.

METHODS

96 women with subclinical hypothyroidism, without thyroid treatment, par-ticipated from a health area in Spain. We studied, among other variables, the presence of depressive symptoms, type of water consumption (tap, bottled or spring) and the level of chlorates in the tap water.

RESULTS

41.7 % (40) of women presented depressive symptoms and these were related to the consumption of tap water (p = 0.001), resulting in a reliable predictor (OR, 27.79; p = 0.007). Chlorate level in the tap water was 250 µg/L, a value within the maximum limit allowed by law.

CONCLUSIONS

chronic exposure to chlorates in water, in women with subclinical hypo-thyroidism, at levels authorized by law, could favor the inhibition of iodine transport and the appearance of depressive symptoms. It would be interesting to test this hy-pothesis as well as its possible effect on other population profiles.

Revalorization of Posidonia oceanica Waste for the Thermochemical Production of Biochar

Every year, many tonnes of Posidonia oceanica are removed from Mediterranean beaches to maintain the quality and pleasure of use of the beaches. Most of this waste ends up in landfills, entailing removal costs. In this work, the Posidonia oceanica material was characterised, and a washing system was developed to obtain biochar. An adequate washing of the starting biomass was shown to play a key role as it led to an over 90% salt content reduction and, therefore, a decrease in conductivity values. The use of biochar as a soil remediator improves soil properties, carbon sequestration, and plant growth. However, not all types of biochars are suitable for this type of application. Therefore, the properties of biochar made from Posidonia Oceanica at different temperatures (300, 400, and 500 °C) were studied. All the biochars obtained showed to exceed 10% organic carbon, which is the lower limit to be applied to soils, the maximum percentage having been obtained at 300 °C. In addition, all presented pH values (8.02, 10.32, and 10.38 for the temperatures of 300, 400, and 500 °C, respectively) that were similar to those of other effective biochars for the remediation of acid soils.

[Common practices and beliefs in the preparation of complementary infant feeding in a Spanish sample: a cross-sectional study]

INTRODUCTION

complementary feeding together with breast milk should cover the nutritional needs of children from 6 months onwards. Thus, inadequate dietary practices can lead to poor nutritional intake. The objective of this study was to examine infant food handling and cooking in Spanish households.

METHODOLOGY

a cross-sectional study was carried out using an online survey in non-institutionalized adults living in Spain who usually prepare infant food for children under 2 years of age.

RESULTS

a total of 1,944 people (37.4 ± 6 years; 65.5 % women) answered the survey. Of these, 72 % prepared mainly mashed foods and 21 % used store-bought baby cereals frequently. Zucchini (39 %), chicken (62 %), hake (64 %) and banana (44 %) were the most commonly used foods. Boiling (63 %) and freezing (59 %) were the most widely used culinary and preservation practices. An inappropriate use of salt and some unsafe foods (large fish and chard) was identified, whereas olive oil and eggs were offered below the current nutritional recommendations.

CONCLUSION

the population surveyed preferred to use mashed foods to feed children under 2 years of age. Even though they were aware that homemade food is nutritionally better, on certain occasions they offer store-bought baby cereal. Furthermore, some inappropriate feeding practices were detected, highlighting the need to implement nutritional education policies regarding infant food preparation.

Groundwater Nitrate Removal Performance of Selected Pseudomonas Strains Carrying nosZ Gene in Aerobic Granular Sequential Batch Reactors

Four granular sequencing batch reactors (GSBRs) were inoculated with four denitrifying Pseudomonas strains carrying nosZ to study the process of granule formation, the operational conditions of the bioreactors, and the carbon concentration needed for nitrate removal. The selected Pseudomonas strains were P. stutzeri I1, P. fluorescens 376, P. denitrificans Z1, and P. fluorescens PSC26, previously reported as denitrifying microorganisms carrying the nosZ gene. Pseudomonas denitrificans Z1 produced fluffy, low-density granules, with a decantation speed below 10 m h−1. However, P. fluorescens PSC26, P. stutzeri I1, and P. fluorescens 376 formed stable granules, with mean size from 7 to 15 mm, related to the strain and carbon concentration. P. stutzeri I1 and P. fluorescens 376 removed nitrate efficiently with a ratio in the range of 96%, depending on the source and concentration of organic matter. Therefore, the findings suggest that the inoculation of GSBR systems with denitrifying strains of Pseudomonas spp. containing the nosZ gene enables the formation of stable granules, the efficient removal of nitrate, and the transformation of nitrate into nitrogen gas, a result of considerable environmental interest to avoid the generation of nitrous oxide.

Evaluation of Drinking Water Quality in Schools in a District Area in Hanoi, Vietnam

BACKGROUND

Drinking water quality affects directly human health. Assessment and prevention of water-borne diseases are crucial for primary prevention, especially for children.

OBJECTIVE

The main aim of this study was to investigate the quality of drinking water from tap water in preschools and primary schools in a district area in Hanoi City, Vietnam.

METHODS

A cross-sectional study was performed from August to October 2019. Water samples from tap water of 154 schools in a district area of Hanoi were collected to determine the quality of drinking water. From each school, at least 2 bottles of water samples were collected on the basis of a standard operating procedure (SOP). Each water sample was analyzed for microbial and physicochemical parameters, including Color, Taste and Odor, Turbidity, pH, Nitrite, Nitrate, Ammonium, Total Iron, Permanganate, Chloride, Hardness, Total Manganese, Sulfate, Arsenic, Coliform, and E.coli, by analytical methods. The obtained values of each parameter were compared with the standard values set by WHO and National Technical Regulation on Domestic Water Quality of Vietnam.

RESULTS

All of the schools employed community water system as a main source for drinking water. The results showed that all tested samples were found to be within the standards for some physicochemical properties, including Color, Taste and Odor, Hardness, Chloride, Total Iron (Fe²⁺ và Fe³⁺), Total Manganese (Mn), Nitrate (NO₃ ^-), Sulfate (SO₄ ^2-), and Total Arsenic (As). On the other hand, some samples did not meet the allowable limits of the national standard, due to pH (3.9%), Turbidity (0.6%), Nitrite (3.2%), Permanganate (6.5%), and Ammonium (5.8%). Furthermore, the microbial data revealed that the substandard water samples from municipal water systems were contaminated by Coliform (9.7%) and/or E.coli (7.8%).

CONCLUSIONS AND RECOMMENDATIONS

Contaminants such as bacterial and chemical agents in to drinking water could be occurred during transport, storage and handling before using by the consumer without regular surveillance. A periodic treatment procedure and monitoring system to keep the level of microbial and chemical contamination of drinking water in schools under control should be performed.

Citizen science charts two major "stomatotypes" in the oral microbiome of adolescents and reveals links with habits and drinking water composition

BACKGROUND

The oral cavity comprises a rich and diverse microbiome, which plays important roles in health and disease. Previous studies have mostly focused on adult populations or in very young children, whereas the adolescent oral microbiome remains poorly studied. Here, we used a citizen science approach and 16S profiling to assess the oral microbiome of 1500 adolescents around Spain and its relationships with lifestyle, diet, hygiene, and socioeconomic and environmental parameters.

RESULTS

Our results provide a detailed snapshot of the adolescent oral microbiome and how it varies with lifestyle and other factors. In addition to hygiene and dietary habits, we found that the composition of tap water was related to important changes in the abundance of several bacterial genera. This points to an important role of drinking water in shaping the oral microbiota, which has been so far poorly explored. Overall, the microbiome samples of our study can be clustered into two broad compositional patterns (stomatotypes), driven mostly by Neisseria and Prevotella, respectively. These patterns show striking similarities with those found in unrelated populations.

CONCLUSIONS

We hypothesize that these stomatotypes represent two possible global optimal equilibria in the oral microbiome that reflect underlying constraints of the human oral niche. As such, they should be found across a variety of geographical regions, lifestyles, and ages.

Metahemoglobinemia in infants over one year

BACKGROUND AND OBJECTIVES

Methaemoglobinaemia is a typical acute intoxication disorder in children under one year old. It is produced by excess nitrates which induce the haemoglobin's iron oxidation, preventing its adequate binding to oxygen. It is more frequent in infants due to its lower enzymatic activity.

PATIENTS

Two cases of 15-month-old infants with methaemoglobinaemia after the intake of vegetables, atypical by the age of the patients and the initial severity in the first case that simulated a septic syndrome. Both cases evolved well with adequate oxygen therapy.

CONCLUSIONS

Although the most frequent clinical manifestation is cyanosis associated with respiratory distress, methaemoglobinaemia can present with more severe and confusing symptoms. The main treatment is oxygen therapy at high concentrations and methylene blue as an intravenous antidote only in selected cases. The intake of vegetables is the main cause of this in infants, so it is important to give adequate information to parents about the consumption and preservation of these foods during the first year of life.

Drinking Water Nitrate and Human Health: An Updated Review

Nitrate levels in our water resources have increased in many areas of the world largely due to applications of inorganic fertilizer and animal manure in agricultural areas. The regulatory limit for nitrate in public drinking water supplies was set to protect against infant methemoglobinemia, but other health effects were not considered. Risk of specific cancers and birth defects may be increased when nitrate is ingested under conditions that increase formation of N-nitroso compounds. We previously reviewed epidemiologic studies before 2005 of nitrate intake from drinking water and cancer, adverse reproductive outcomes and other health effects. Since that review, more than 30 epidemiologic studies have evaluated drinking water nitrate and these outcomes. The most common endpoints studied were colorectal cancer, bladder, and breast cancer (three studies each), and thyroid disease (four studies). Considering all studies, the strongest evidence for a relationship between drinking water nitrate ingestion and adverse health outcomes (besides methemoglobinemia) is for colorectal cancer, thyroid disease, and neural tube defects. Many studies observed increased risk with ingestion of water nitrate levels that were below regulatory limits. Future studies of these and other health outcomes should include improved exposure assessment and accurate characterization of individual factors that affect endogenous nitrosation.