T. Minh

Determining Heavy Metal Concentrations in Residential and Automobile Garage Dust in Hanoi, Vietnam

This study describes a method for determining the heavy metal content in 20 indoor and garage dust samples in Hanoi using inductively coupled plasma mass spectrometry (ICP-MS). The samples were processed using a microwave wet inorganic decomposition technique. The results showed that most of the surveyed metal elements were present in the dust samples. Fe and Zn were the two elements with the highest concentrations and were most commonly found in the most samples compared to other metals. Highly toxic metals such as Pb, Hg, As, Ni, etc., were detected in all samples studied. The metal content is arranged in decreasing order: Fe > Zn > Mn > Pb > Cu > Cr > As > Se > Hg > Sb > Cd > Ag > V. The Fe content is approximately 3339 µg/g – 132522 µg/g, followed by Zn in the range of 1371 µg/g – 11222 µg/g. The metals Cr, Pb, Cu, Ni, Co, and B are in the range of 0,220 µg/g – 305,5 µg/g. For highly toxic elements such as As, Sb, Hg, and Cd, the recorded content is lower, fluctuating between 0,070 µg/g – 30,020 µg/g. The research results provide important data on the levels of heavy metal pollution in urban environmental dust, contributing to the assessment of exposure risks and potential impacts on human health.

Overview on Polycyclic Aromatic Compounds in Water and Sediment Samples in Vietnam

Polycyclic aromatic compounds (PACs), notably unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs and Me-PAHs), are a group of organic pollutants consisting of two or more fused aromatic rings. They are primarily generated through the incomplete combustion of organic materials and exhibit high toxicity, bioaccumulation potential, and various adverse impacts on ecosystems and human health. The contamination status and distribution characteristics of PAHs and Me-PAHs have been investigated through several case studies in various aquatic ecosystems across Vietnam. However, information about the analytical chemistry and environmental occurrence of PACs in Vietnamese water and sediment samples has not been comprehensively reviewed. Analytical procedures for PAHs in water and sediment typically comprise three main steps: solvent extraction, extract purification, and quantification by gas chromatography-mass spectrometry (GC-MS) or high-performance liquid chromatography with fluorescence detection (HPLC-FLD). PAHs have been frequently detected in Vietnamese water and sediment samples at low to moderate concentration levels. Low-molecular-weight PAHs (LMW-PAHs, 2 to 3 rings) are dominant compounds in water, while high-molecular-weight PAHs (HMW-PAHs, 4 rings or more) tend to accumulate in sediment. Pyrogenic sources are estimated to be more abundant than petrogenic sources. The urbanization process and waste processing activities are major contributors to the emission of PAHs and their derivatives. Additional comprehensive and continuous studies on the analysis and assessment of PACs in Vietnamese aquatic environment are needed.

Widespread occurrence of volatile methyl siloxanes in settled dust from three regions in Vietnam: Geographical variations, indoor-outdoor differences, and human exposure assessment.