Chemical characterization and source apportionment of ambient nanoparticles: a case study in Hanoi, Vietnam.

PM0.1 has been believed to have adverse short- and long-term effects on human health. However, the information of PM0.1 that is needed to fully evaluate its influence on human health and environment is still scarce in many developing countries. This is a comprehensive study on the levels, chemical compositions, and source apportionment of PM0.1 conducted in Hanoi, Vietnam. Twenty-four-hour samples of PM0.1 were collected during the dry season (November to December 2015) at a mixed site to get the information on mass concentrations and chemical compositions. Multiple linear regression analysis was utilized to investigate the simultaneous influence of meteorological factors on fluctuations in the daily levels of PM0.1. Multiple linear regression models could explain about 50% of the variations of PM0.1 concentrations, in which wind speed is the most important variable. The average concentrations of organic carbon (OC), elemental carbon (EC), water-soluble ions (Ca2+, K+, Mg2+, Na+, NH4+, Cl-, NO3-, SO42-, C2O42-), and elements (Be, Al, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba, Tl, Pb, Na, Fe, Mg, K, and Ca) were 2.77 ± 0.90 µg m-3, 0.63 ± 0.28 µg m-3, 0.88 ± 0.39 µg m-3, and 0.05 ± 0.02 µg m-3, accounting for 51.23 ± 9.32%, 11.22 ± 2.10%, 16.28 ± 2.67%, and 1.11 ± 0.94%, respectively. A positive matrix factorization model revealed the contributions of five major sources to the PM0.1 mass including traffic (gasoline and diesel emissions, 46.28%), secondary emissions (31.18%), resident/commerce (12.23%), industry (6.05%), and road/construction (2.92%).

Survey reveals slow strides in promoting adolescent reproductive health in Vietnam.

PIP: This article presents the findings of a survey evaluating the adolescent reproductive health program by the Vietnamese Government. Conducted by the Population Research Consultants, survey findings revealed several setbacks of the adolescent reproductive health program; these included the following: 1) adolescents favor radio, television and newspapers as sources of reproductive health (RH) information; 2) adolescents have no knowledge of pregnancy, sexually transmitted diseases, and HIV/AIDS prevention; 3) the demand for RH information varies according to the sociodemographic characteristics of respondents; 4) while the majority of adolescents do not favor premarital sex and premarital pregnancy, their choice is to keep and deliver the baby in case of a premarital pregnancy; 5) adolescents give a poor rating to the quality of RH/family planning services at the centers; 6) adolescents need to further understand RH but not knowing its meaning, they cannot tell what type of information they require; 6) adolescents have poor knowledge of adolescent reproductive health; 7) friendship and love are often discussed among adolescents, but sexuality rarely is; and 8) adolescents have poor knowledge of RH and poor interest in RH/family planning service facilities.^ieng