Excessive intake of fluoride can cause adverse health effects. Consumption of tea as a popular drink could be a potential source of fluoride exposure to humans. This research aimed to evaluate the fluoride concentration in tea among the Iranian people using the available data in the literature and to assess the health risk related to the consumption of tea in men, women, and children. The health risk assessment was conducted using the chronic daily intake and hazard quotient according to the approach suggested by the Environmental Protection Agency. The fluoride content in published studies varied noticeably, ranging from 0.13 to 3.27 mg/L. The results revealed that the hazard quotient (HQ) in age groups of women (21–72 years) and children (0–11 years) was within the safe zone (HQ < 1) which showed that there was no potential of non-carcinogenic risk associated with drinking tea in these groups. However, in one case of the men (21–72 years), the HQ > 1 which shows a probable risk of fluorosis. The order of non-carcinogenic health risks in the studied groups was in the order of men > women > children. The results of this can be useful for organizations with the responsibility of human health promotion.

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An (Fe, Ag) co-doped ZnO nanostructure was synthesized by a simple chemical co-precipitation method and used for the degradation of dibutyl phthalate (DBP) in aqueous solution under visible light-emitting diode (LED) irradiation. (Fe, Ag) co-doped ZnO nanorods were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, UV-VIS diffuse reflectance spectroscopy, elemental mapping, Field emission scanning electron microscopy, transmission electron microscope and Brunauer-Emmett-Teller surface area analysis. A Central Composite Design was used to optimize the reaction parameters for the removal of DBP by the (Fe, Ag) co-doped ZnO nanorods. The four main reaction parameters optimized in this study were the following: pH, time of radiation, concentration of the nanorods and initial DBP concentration. The interaction between the four parameters was studied and modeled using the Design Expert 10 software. A maximum reduction of 95% of DBP was achieved at a pH of 3, a photocatalyst concentration of 150 mg L and a DBP initial DBP concentration of 15 mg L. The results showed that the (Fe, Ag) co-doped ZnO nanorods under low power LED irradiation can be used as an effective photocatalyst for the removal of DBP from aqueous solutions.

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Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.

Background: Evaluation of the various types of water reveal that groundwater comprises 99% of the earth’s available fresh water. Many factors affect the type and degree of mineralization, as well as the natural radionuclides content in these types of water. The consumption of bottled natural mineral water, which comes from groundwater, among Iranians is gradually increasing. Therefore, the detection of high concentrations of radionuclides, associated with consumption of groundwater, is proposed as a public health problem in several areas. Methods: In this study, the activity concentration of natural radionuclides such as 226Ra, 228Ra, 210Pb, and 40K, annual effective dose for three age groups (<1 year, 7-12 years, and >17 years), and excess lifetime cancer risk due to the ingestion of natural radionuclides present in 70 different commercial bottled mineral waters from most provinces of Iran, were evaluated. Activity concentrations were measured using gamma spectrometry and a high purity germanium detector (HPGe). Results: The results showed that the activity concentrations of natural radionuclides were higher than those reported in the same studies in other countries. Also, the annul effective dose for the three age groups was much higher than the recommended value (0.1 mSvyr-1), as reported by the WHO. The excess lifetime cancer risk for three radionuclides, 226Ra, 228Ra, and 40K, were less than the acceptable value of 10-3 for radiological risk, while the risk for 210Pb was higher than the recommended value. Conclusion: According to the results of this study, the frequent use of bottled waters produced in different provinces of Iran possess health hazards to consumers.

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