Contents and mass balances of cadmium and arsenic in a wastewater-fed fish pond of Hoang Mai, Hanoi, Vietnam.

Wastewater-fed aquatic production has been practiced since the 1960s in peri-urban Hanoi. Wastewater is used as a cheap and reliable source of both water and nutrients but there is a risk that it may lead to accumulation of potentially toxic elements (PTEs) in the production systems and produce and thereby constitute a food safety risk. This study investigates the cadmium (Cd) and arsenic (As) concentrations in water, sediment, plant and fish of a wastewater fed-fish pond in Hoang Mai district, Hanoi, Vietnam. Cd concentrations in the water were lower than the Vietnamese quality guidelines (0.8-1.8 µg Cd/L) for protection of aquatic life but As concentrations in inlet and outlet water of 44.3 and 21.3 µg/L, respectively both were higher that the guidelines (20 µg As/L) and may cause toxicity to fish in the pond and the surrounding vegetable farms using the outlet water for irrigation. The concentrations of Cd and As in fish and Cd in water spinach did not constitute a food safety risk. However, As concentrations in water spinach may be of concern. A mass balance estimate for the fish pond showed that about 12% of the incoming As accumulate in suspended particular matters, 40% settle down to the sediment, less than 0.1% accumulate in the fish and water spinach and 48% overflow with the pond effluent. The concentrations of Cd were too low to make a mass balance for the fish pond.

Children's Environmental Health in South and Southeast Asia: Networking for Better Child Health Outcomes.

Children are particularly vulnerable to environmental hazards because they receive higher doses of pollutants in any given environment and often do not have equitable access to social protection mechanisms such as environmental and health care services. The World Health Organization established a global network of collaborating centres that address children's environmental health (CEH). The network developed a focus on low- and middle-income countries (LMICs) and is broadening its reach by conducting regional workshops for CEH.Objective: This paper reports on the outcomes of a workshop held in conjunction with the 17th International Conference (November 2017) of the Pacific Basin Consortium for Environment and Health, focused on the state of CEH in South and Southeast Asia as presented by seven countries from the region (India, Bangladesh, Nepal, Bhutan, Vietnam, Thailand, Sri Lanka).Workshop outcomes: Country reports presented at the meeting show a high degree of similarity with respect to the issues threatening the health of children. The most common problems are outdoor and household air pollution in addition to exposure to heavy metals, industrial chemicals, and pesticides. Many children still do not have adequate access to clean water and improved sanitation while infectious diseases remain a problem, especially for children living in poverty. Child labour is widely prevalent, generally without adequate training or personal protective equipment. The children now face the dual burden of undernutrition and stunting on the one hand and overnutrition and obesity on the other.Conclusion: It is evident that some countries in these regions are doing better than others in varying areas of CEH. By establishing and participating in regional networks, countries can learn from each other and harmonise their efforts to protect CEH so that all can benefit from closer interactions.