Levels and daily intake of lead (Pb) and six essential elements in gari samples from Ondo State, Southwest Nigeria: A potential risk factor of health status

Characterization of Micronutrients in Tofu from Several Cities in Java Island Indonesia

Tofu is a traditional food such as curd made from soymilk with additional coagulants which is widely consumed by people in Indonesia and Asian countries. Tofu is one of the important sources of micronutrients, such as cobalt (Co), chromium (Cr), iron (Fe), selenium (Se) and zinc (Zn). Therefore, the content of various elements both toxic and essential need to be studied to ensure the food safety and estimating their contribution to daily intake.

METHODS

In this research, the determination of micronutrient content in tofu was carried out in the samples collected from traditional market in Jakarta, Yogyakarta, West, Central and East Java Provinces during the period 2010-2014. Determination of elemental concentration was carried out using neutron activation analysis (NAA) methods.

RESULTS

Analysis result showed that the elemental concentrations of Co, Cr, Fe, Se and Zn in tofu were in the range of 0.001-0.27; ≤0.001-0.35; ≤0.050-62.90; ≤0.0046-5.34 and 0.02-21.19 mg/kg respectively. The daily intake value of tofu is calculated by estimating their contribution based on the concentration and consumption data. The average daily intake of Co, Cr, Fe, Se and Zn contributes to 1.33-11.95; 2.10-2.93; 2.66-5.99, 13.1 and 1.95-2.69% of RDA values for adult women and men.

CONCLUSIONS

The analysis shows that there are variations in the concentration of micronutrients contained in tofu from the five provinces. Tofu has contributed RDA of Co, Cr, Fe, Se, and Zn in almost all regions observed, tofu consumption contributed only a low fraction of RDA value for an adult.

Manganese in the Diet: Bioaccessibility, Adequate Intake, and Neurotoxicological Effects

Manganese (Mn) is an essential element that participates in several biological processes. Mn serves as a cofactor for several enzymes, such as glutamine synthetase and oxidoreductases, that have an important role in the defense of the organisms against oxidative stress. The diet is the main source of Mn intake for humans, and adequate daily intake levels for this metal change with age. Moreover, in higher amounts, Mn may be toxic, mainly to the brain. Here, we provide an overview of Mn occurrence in food, addressing its bioaccessibility and discussing the dietary standard and recommended intake of Mn consumption. In addition, we review some mechanisms underlying Mn-induced neurotoxicity.

Arsenic, cadmium, and mercury-induced hypertension: mechanisms and epidemiological findings

Arsenic (As), cadmium (Cd), and mercury (Hg) are toxic elements widely distributed in the environment. Exposure to these elements was attributed to produce several acute and chronic illnesses including hypertension. The aim of this review is to provide a summary of the most frequently proposed mechanisms underlying hypertension associated with As, Cd, and Hg exposure including: oxidative stress, impaired nitric oxide (NO) signaling, modified vascular response to neurotransmitters and disturbed vascular muscle Ca²⁺ signaling, renal damage, and interference with the renin-angiotensin system. Due to the complexity of the vascular system, a combination rather than a singular mechanism needs to be considered. In addition, epidemiological findings showing the relationship between various biomarkers of metal exposure and hypertension are described. Given the complex etiology of hypertension, further epidemiological studies evaluating the roles of confounding factors such as age, gender, and life style are still necessary.

Identifying the Gaps in Practice for Combating Lead in Drinking Water in Hong Kong

Excessive lead has been found in drinking water in Hong Kong in tests carried out in 2015. Investigations have identified that the problem in public rental housing estates was caused by the problematic solders used in the plumbing, and recommendations on enhancing the quality control system and strengthening the relevant water quality standards have been proposed. The cause for the same problem happening in other premises where soldering has not been adopted for water pipe connections is left unidentified. Considering the unidentified cause and the recommendations made, this study aims to identify the gaps in practice followed in Hong Kong for safeguarding the water quality of new installations. A holistic review of governing ordinances and regulations, products and materials used and the testing and commissioning requirements adopted in Hong Kong and elsewhere in the world were conducted. Based on international practices and parametric analysis, it was found that there are gaps in practices followed in Hong Kong, which are directly and indirectly leading to the lead-in-water crisis. Recommendations for improvement in the quality control system, and the water quality standards including the allowable lead content and leaching limit for products and materials and the testing and commissioning requirements on plumbing installations have been made. The review and the identified gaps would become useful reference for countries in strengthening their relevant water quality standards.