Contamination of Bisphenol A, Nonylphenol, Octylphenol, and Estrone in Major Rivers of Mega Manila, Philippines.

Endocrine-disrupting compounds (EDCs) such as natural and synthetic hormones as well as phenolic industrial chemicals are considered contaminants of emerging concern in environmental waters. While EDCs carried through rivers may impact ecosystem health and productivity, these compounds are still not widely studied nor regulated. In the present study, we report the occurrence of EDCs in urban rivers in Mega Manila, namely, the Marikina, Pasig, Angat, and Pampanga Rivers that drain into Manila Bay. Endocrine-disrupting compounds may have reached these rivers through domestic wastewater and industrial effluents. Water samples from the rivers were extracted by solid-phase extraction before instrumental analysis using a liquid chromatograph coupled to a mass spectrometer. The analytical method exhibited good linear response (>99% in the concentration range of 1-50 µg/L) and low instrument detection limits (0.14-1.46 µg/L) for the hormones estrone (E1), estradiol, ethinylestradiol, progesterone, and testosterone, and the industrial chemicals bisphenol A, nonylphenol, and octylphenol. Of the hormones, E1 was detected up to 11 ng/L. Bisphenol A, nonylphenol, and octylphenol were measured up to 54, 1878, and 62 ng/L, respectively. Endocrine-disrupting compounds are not yet monitored in water bodies in the Philippines and there are no local guidelines yet on occurrence, pollution prevention, and mitigation. Environ Toxicol Chem 2024;43:259-266. © 2023 SETAC.

Occurrence and distribution of hormones and bisphenol A in Laguna Lake, Philippines.

The occurrence of hormones and hormone-like compounds in water has been regarded as an emerging environmental concern. These water contaminants are known to cause endocrine disruption that may affect aquatic organisms. In this study, hormones and phenolic xenoestrogens were investigated and measured in the surface waters of Laguna Lake, Philippines. Laguna Lake is the largest lake in the country that has many uses including fish cultivation and source for potable water production. The hormones estrone, 17-beta-estradiol, 17-alpha-ethynylestradiol, progesterone and testosterone as well as the plasticizer bisphenol A in the lake water were determined by solid phase extraction and LC-MS/MS. The extraction method exhibited good recoveries (75-90% in spiked lake water) while the instrumental method of analysis has low detection limits (0.01-0.24 µg/L) and good linear response (>99% in the 0-50 µg/L concentration range). In the nine sampling sites across the lake, estrone was found in concentrations between 0.03 and 0.30 ng/L. 17-Beta-estradiol, testosterone and progesterone were detected in some of the sites in concentrations up to 0.36, 0.22, and 2.05 ng/L, respectively. Bisphenol A was detected in all sites in higher concentrations of 0.71-47.40 ng/L. Although there are no local guidelines yet, the determination and monitoring of these emerging water contaminants are important because of their potential environmental impacts. Further to this initial study, investigations on point sources spanning the tributary rivers, long-term determination of locational and temporal variations, and assessment of ecotoxicological risks are needed. These are crucial in the regulation and mitigation of discharges into the lake.

Decabromodiphenyl ether in indoor dust from different microenvironments in a university in the Philippines.

This study was conducted to develop a method for the determination of decabromodiphenyl ether (BDE-209) in indoor dust from different microenvironments in a university in the Philippines. BDE-209 was extracted from dust samples by ultrasonication and determined by HPLC-UV. The determination was performed using external calibration and internal standard calibration. Internal standard calibration was shown to be more precise and sensitive than external calibration. The linearity for the concentration range of 0-300 µg L(-1) BDE-209 was good (R(2)=0.993). The % absolute recovery and the % RSD for n=8 spiked dust analysis based on a 0.2 g dust sample was 57% and 19%, respectively. The method detection limit was 285 ng g(-1). All dust samples showed detectable levels of BDE-209 with some at levels below the quantification limits. The concentrations of BDE-209 in the quantified samples are within the range of 1103-4117 ng g(-1) with an average concentration of 2172 ng g(-1). The levels of BDE-209 found in the dust samples are comparable to those reported in house and workplace dusts from other Asian countries. Although not conclusive, it has been shown empirically that BDE-209 concentrations are higher in sampling sites containing more possible BDE-209 sources like electrical and electronic equipment.

Occurrence and sources of bromate in chlorinated tap drinking water in Metropolitan Manila, Philippines.

Significant levels of potentially carcinogenic bromate were measured in chlorinated tap drinking water in Metropolitan Manila, Philippines, using an optimized ion-chromatographic method. This method can quantify bromate in water down to 4.5 µg l⁻¹ by employing a postcolumn reaction with acidic fuchsin and subsequent spectrophotometric detection. The concentration of bromate in tap drinking water samples collected from 21 locations in cities and municipalities within the 9-month study period ranged from 7 to 138 µg l⁻¹. The average bromate concentration of all tap drinking water samples was 66 µg l⁻¹ (n = 567), almost seven times greater than the current regulatory limit in the country. The levels of bromate in other water types were also determined to identify the sources of bromate found in the distribution lines and to further uncover contaminated sites. The concentration of bromate in water sourced from two rivers and two water treatment plants ranged from 15 to 80 and 12 to 101 µg l⁻¹, respectively. Rainwater did not contribute bromate in rivers but decreased bromate level by dilution. Groundwater and wastewater samples showed bromate concentrations as high as 246 and 342 µg l⁻¹, respectively. Bromate presence in tap drinking water can be linked to pollution in natural water bodies and the practice of using hypochlorite chemicals in addition to gaseous chlorine for water disinfection. This study established the levels, occurrence, and possible sources of bromate in local drinking water supplies.