Background Growing evidence indicates that in utero arsenic exposures in humans may increase the risk of adverse health effects and development of diseases later in life. This study aimed to evaluate potential health risks of in utero arsenic exposure on genetic damage in newborns in relation to maternal arsenic exposure. Methods A total of 205 pregnant women residing in arsenic-contaminated areas in Hanam province, Vietnam, were recruited. Prenatal arsenic exposure was determined by arsenic concentration in mother’s toenails and urine during pregnancy and in umbilical cord blood collected at delivery. Genetic damage in newborns was assessed by various biomarkers of early genetic effects including oxidative/nitrative DNA damage (8-hydroxydeoxyguanosine, 8-OHdG, and 8-nitroguanine), DNA strand breaks and micronuclei (MN) in cord blood. Results Maternal arsenic exposure, measured by arsenic levels in toenails and urine, was significantly increased ( p <  0.05) in subjects residing in areas with high levels of arsenic contamination in drinking water. Cord blood arsenic level was significantly increased in accordance with maternal arsenic exposure ( p <  0.001). Arsenic exposure in utero is associated with genotoxic effects in newborns indicated as increased levels of 8-OHdG, 8-nitroguanine, DNA strand breaks and MN frequency in cord blood with increasing levels of maternal arsenic exposure. Maternal toenail arsenic level was significantly associated with all biomarkers of early genetic effects, while cord blood arsenic levels associated with DNA strand breaks and MN frequency. Conclusions In utero arsenic exposure is associated with various types of genetic damage in newborns potentially contributing to the development of diseases, including cancer, later in life.

Inhalable particulate matter (PM) is a health concern, and people living in large cities such as Bangkok are exposed to high concentrations. This exposure has been linked to respiratory and cardiac diseases and cancers of the lung and brain. Throughout 2018, PM was measured in northern Bangkok near a toll road (13.87°N, 100.58°E) covering all three seasons (cool, hot and rainy). PM10 was measured in 24- and 72-h samples. On selected dates aerodynamic size and mass distribution were measured as 3-day samples from a fixed 5th floor inlet. Particle number concentration was measured from the 5th floor inlet and in roadside survey measurements. There was a large fraction of particle number concentration in the sub-micron range, which showed the greatest variability compared with larger fractions. Metals associated with combustion sources were most found on the smaller size fraction of particles, which may have implications for associated adverse health outcomes because of the likely location of aerosol deposition in the distal airways of the lung. PM10 samples varied between 30 and 100 μg m−3, with highest concentrations in the cool season. The largest metal fractions present in the PM10 measurements were calcium, iron and magnesium during the hot season with average airborne concentrations of 13.2, 3.6 and 2.0 μg m−3, respectively. Copper, zinc, arsenic, selenium, molybdenum, cadmium, antimony and lead had large non-crustal sources. Principal component analysis (PCA) identified likely sources of the metals as crustal minerals, tailpipe exhaust and non-combustion traffic. A health risk analysis showed a higher risk of both carcinogenic and non-carcinogenic health effects in the drier seasons than the wet season due to ingestion of nickel, arsenic, cadmium and lead. Graphical abstract

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&lt;p&gt;Airborne particulate matter is known to be deleterious to human health and exceeds exposure limits in many large cities. Some heavy metals and metalloids are known carcinogens and have been measured as constituents of PM in Bangkok air. There is growing interest in the sub-micron and ultrafine (&lt; 100 nm) fractions due to their deeper penetration in the lung. Identifying distribution of metals over the size range can provide information on the metals source as well as providing information on the likely exposure to those particles.&lt;/p&gt;&lt;p&gt;Three sites, owned and managed by the Thailand Pollution Control Department, were identified to provide contrasting particulate samples in a measurement campaign during 2018. The Ayutthaya site was located within the grounds of a school, 80 km to the north of Bangkok. The site was chosen as concentrations due to city traffic would be lower and could be considered a reference site. The Bang Phli site was situated in an industrial area 50 km to the south-east of Bangkok, in an area near industry. The Chok Chai site was in central Bangkok near to a busy road.&lt;/p&gt;&lt;p&gt;At each site, three 3-day weekend and 3-day weekday gravimetric samples of size differentiated mass were drawn using an Electrical Low Pressure Impactor (ELPI; Dekati, Finland) over 12 size fractions in six different study visits. These were chosen to enable three measurements over the rainy season and three in the dry season. Each size fraction was weighed and then analysed by inductively coupled plasma mass spectroscopy to find the concentration of 17 elements (Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba and Pb). The ELPI also measured particle number concentration at 1 Hz.&amp;#160;&lt;/p&gt;&lt;p&gt;The number concentration of aerosol was highest in the Chok Chai roadside site, and lowest in the Ayutthaya background site. Al concentration was the highest in all three locations, with an average concentration over all measurements of 1909, 1012 and 1576 ng m&lt;sup&gt;-3&lt;/sup&gt; in Ayutthaya, Bang Phli and Chok Chai respectively. Concentrations of Al, Cr, Mg and Fe were typically higher than 100 ng m&lt;sup&gt;-3&lt;/sup&gt; in all sites, Cu and Zn higher than 10 ng m&lt;sup&gt;-3&lt;/sup&gt; and the rest lower.&lt;/p&gt;&lt;p&gt;The shape of the metal distributions was consistent across all three sites for specific metals. Mg, Al, Cr, Mo, Ni and Cu could be described as having a flat distribution across all measured size distributions V, Mn, Cd, Sb, Pb, Zn As and Se had a peak in the sub-micron range, while Fe, Ba and Co peaked above 1 &amp;#181;m.&lt;/p&gt;&lt;p&gt;Some seasonal effects could be seen across all three locations, these included an increase in Al, Cr and Fe during four measurements in dry season (November, 2018). This was particularly observed at Ayutthaya, where total measurements of Al were between 4862 and 5961 ng m&lt;sup&gt;-3&lt;/sup&gt;, when all other measurements were between 98 and 264 ng m&lt;sup&gt;-3&lt;/sup&gt;, suggesting a strong local source.&lt;/p&gt;

Traffic is a major source of particulate pollution in large cities, and particulate matter (PM) level in Bangkok often exceeds the World Health Organisation limits. While PM2.5 and PM10 are both measured in Bangkok regularly, the sub-micron range of PM, of specific interest in regard to possible adverse health effects, is very limited. In the study, particle number concentration (PNC) was measured on public transport in Bangkok. A travel route through Bangkok using the state railway, the mass rapid transport underground system, the Bangkok Mass Transit System (BTS) Skytrain and public buses on the road network, with walking routes between, was taken whilst measuring particle levels with a hand-held concentration particle counter. The route was repeated 19 times covering different seasons during either morning or evening rush hours. The highest particle concentrations were found on the state railway, followed by the bus, the BTS Skytrain and the MRT underground with measured peaks of 350,000, 330,000, 33,000 and 9000 cm−3, respectively, though particle numbers over 100,000 cm−3 may be an underestimation due to undercounting in the instrument. Inside each form of public transport, particle numbers would peak when stopping to collect passengers (doors opening) and decay with a half-life between 2 and 3 min. There was a weak correlation between particle concentration on bus, train and BTS and Skytrain with carbon monoxide concentration, as measured at a fixed location in the city.