Diarrhoea, malnutrition, and dehydration associated with school water, sanitation, and hygiene in Metro Manila, Philippines: A cross-sectional study

INTRODUCTION

Diarrhoea, malnutrition, and dehydration threaten the lives of millions of children globally due to inadequate water, sanitation, and hygiene (WaSH). Our study aimed to identify environmental and behavioural risk factors of these health outcomes among schoolchildren in Metro Manila, Philippines.

MATERIALS AND METHODS

We analysed data from a multistage cluster sample of schoolchildren in grades 5, 6, 7, 9, and 10 (ages ~10-15 years old) to investigate WaSH facilities and hygiene practices. Outcomes were: self-reported diarrhoea, measured via questionnaire; observed malnutrition (stunting, undernutrition [underweight/thin and wasted/severely thin], over-nutrition [overweight and obese]), measured via anthropometry; dehydration, measured via urine specific gravity/urine test strips. We used multiple logistic regression to explore correlates.

RESULTS

We included 1558 students from 15 schools in three cities. Over 28% (421) of students had diarrhoea and 68% (956) were dehydrated. Over 15% (227) of students were stunted, ~9% (127) were undernourished, and >21% (321) were over-nourished. Diarrhoea was associated with poor handwashing, while dehydration was associated with the lack of water in school restrooms. Stunting was linked with not using the school restroom, the lack of water in school restrooms, and the lack of hygiene lessons in school. Undernutrition was associated with the lack of a school restroom cleaning policy. Risks of diarrhoea, stunting, and undernutrition decreased as the number of school restrooms increased. Risks of stunting and overnutrition decreased as the numbers of school toilets increased. Having more than seven handwashing basins was associated with decreased risk of dehydration.

DISCUSSION

Findings from our cross-sectional study cannot describe causation. We have found associations that suggest that school restroom cleaning policies, adequate water supply, improved handwashing, and hygiene education are needed to prevent disease. School-based WaSH interventions are recommended to provide water in school WaSH facilities, promote handwashing, and improve hygiene-related knowledge.

PM10 and surface dust source characterization in Baguio City Central Business District (CBD), Philippines

This study measured both PM₁₀ and surface dust concentrations at roadside in the Central Business District of Baguio City. A total of 66 PM₁₀ filters and 25 surface dust samples were analyzed for 14 metals (Na, Mg, Al, Ca, Cr, Mn, Co, Ni, Cu, Zn, As, Sr, Cd and Pb) using inductively coupled plasma mass spectrometer ICP-MS to characterize sources of airborne particulate matter (APM). Calculation of enrichment factors indicated elements Zn, Cd, Pb and As to be enriched in both PM₁₀ and surface dust samples. The compositional signature of local surface dust was found to be strongly correlated with that of PM₁₀ particles. Enrichment Factor, Conditional Probability Function (CPF), Correlation Analysis and Principal component analysis were applied to determine sources affecting the Baguio CBD area, and results indicate three APM contributing sources (1) soil sources and (2) soil-road dust resuspension and vehicular emissions (3) vehicular emissions. The NE and SW wind sectors were dominant for most of the identified sources.

Oxidative potential of fine ambient particles in various environments

The oxidative potential (OP) and chemical characteristics of fine particles collected from urban, roadside, rural, and industrial sites in Korea during spring, summer, fall, and winter seasons and an urban site in the Philippines during dry and wet seasons were examined. Significant differences in the OP of fine particles among sites and seasons were found. The industrial site yielded the highest OP activity (both mass and volume-normalized OP) among the sites, suggesting the strongest reactive oxygen species (ROS)-generating capability of industry source-dominant PM_2.5. Seasonal data show that OP activities increased during the spring and summer possibly due to increased heavy metals caused by dust events and secondary organic aerosols formed by strong photochemical activity, respectively. The strength of the OP association with the chemical components highlights the influence of organic carbon and transition metals on the OP of ambient fine particles. The two OP assays (dithiothreitol (DTT) and electron spin resonance (ESR)) having different ROS-generating mechanisms were found to have different sensitivities to the chemical components facilitating a complementary analysis of the OP of ambient fine particles. Multiple linear regression model equations (OP as a function of chemical components) which were dependent on the sites were derived. A comparison of the daily OP and hazard index (HI) (the ratio of the measured mass concentration to the reference mass concentration of fine particles) suggests that the HI may not be sufficient to accurately estimate the health effects of fine particles, and a direct or indirect measurement of toxicity such as OP should be required in addition to the concentration level.

Time-resolved measurements of PM2.5 carbonaceous aerosols at Gosan, Korea

In order to better understand the characteristics of atmospheric carbonaceous aerosol at a background site in Northeast Asia, semicontinuous organic carbon (OC) and elemental carbon (EC), and time-resolved water-soluble organic carbon (WSOC) were measured by a Sunset OC/ EC and a PILS-TOC (particle-into-liquid sampler coupled with an online total organic carbon) analyzer, respectively, at the Gosan supersite on Jeju Island, Korea, in the summer (May 28-June 17) and fall (August 24-September 30) of 2009. Hourly average OC concentration varied in the range of approximately 0.87-28.38 microgC m-3, with a mean of 4.07+/- 2.60 microgC m-3, while the hourly average EC concentration ranged approximately from 0.04 to 8.19 .microgC m-3, with a mean of 1.35 +/- 0.71 microgC m-3, from May 28 to June 17, 2009. During the fall season, OC varied in the approximate range 0.9-9.6 microgC m-3, with a mean of 2.30 +/-0.80 microgC m-3, whereas EC ranged approximately from 0.01 to 5.40 microgC m-3, with a mean of 0.66 +/- 0.38 microgC m-3. Average contributions of EC to TC and WSOC to OC were 26.0% +/- 9.7% and 20.6% +/-7.4%, and 37.6% +/- 23.5% and 57.2% +/- 22.2% during summer and fall seasons, respectively. As expected, clear diurnal variation of WSOC/OC was found in summer, varying from 0.22 during the nighttime up to 0.72 during the daytime, mainly due to the photo-oxidation process. In order to investigate the effect of air mass pathway on the characteristics of carbonaceous aerosol, 5-day back-trajectory analysis was conducted using the HYSPLIT model. The air mass pathways were classified into four types: Continental (CC), Marine (M), East Sea (ES) and Korean Peninsula (KP). The highest OC/EC ratio of 3.63 was observed when air mass originated from the Continental area (CC). The lowest OC/EC ratio of 0.79 was measured when air mass originated from the Marine area (M). A high OC concentration was occasionally observed at Gosan due to local biomass burning activities. The contribution of secondary OC to total OC varied approximately between 8.4% and 32.2% and depended on air mass type.

Observed chemical characteristics of long-range transported particles at a marine background site in Korea

Deokjeok Island is located off the west coast of the Korean Peninsula and is a suitable place to monitor the long-range transport of air pollutants from the Asian continent. In addition to pollutants, Asian dust particles are also transported to the island during long-range transport events. Episodic transport of dust and secondary particles was observed during intensive measurements in the spring (March 31-April 11) and fall (October 13-26) of 2009. In this study, the chemical characteristics of long-range-transported particles were investigated based on highly time-resolved ionic measurements with a particle-into-liquid system coupled with an online ion chromatograph (PILS-IC) that simultaneously measures concentrations of cations (Li+, Na , NH4+, K+, Ca2+, Mg2+) and anions (F-, C1-, NO3-, SO42-). The aerosol optical thickness (AOT) distribution retrieved by the modified Bremen Aerosol Retrieval (M-BAER) algorithm from moderate resolution imaging spectroradiometer (MODIS) satellite data confirmed the presence of a thick aerosol plume coming from the Asian continent towards the Korean peninsula. Seven distinctive events involving the long-range transport (LRT) of aerosols were identified and studied, the chemical components of which were strongly related to sector sources. Enrichment of acidic secondary aerosols on mineral dust particles, and even of sea-salt components, during transport was observed in this study. Backward trajectory, chemical analyses, and satellite aerosol retrievals identified two distinct events: a distinctively high [Ca2++Mg2]/[Na+] ratio (>2.0), which was indicative of a preprocessed mineral dust transport event, and a low [Ca2++Mg2+]/[Na+] ratio (<2.0), which was indicative of severe aging of sea-salt components on the processed dust particles. Particulate C1- was depleted by up to 85% in spring and 50% in the fall. A consistent fraction of carbonate replacement (FCR) averaged 0.53 in spring and 0.55 in the fall. Supporting evidences of C1- enrichment on the marine boundary layer prior to a dust front were also found. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for sector and air mass classifications of clean and LRT cases.

Organochlorine pesticides in ambient air in selected urban and rural residential areas in the Philippines derived from passive samplers with polyurethane disks

The passive sampler with PUF disk was applied to investigate the types and concentrations of organochlorine pesticides (OCPs) in ambient air in three urban and rural residential areas simultaneously at different weather conditions in the Philippines. The concentrations of OCPs derived from the passive samplers indicated clear distinctions in the predominance of certain types and amounts of OCPs in air at different sampling sites and periods of sampling. Chlordanes were detected in concentrations ranging from 218 to 2,324 pg/m³ in the urban residential sites in all the sampling periods, indicating the possible use of these pesticides as termiticides in houses. Endosulfans were detected in two rural sites at 491 pg/m³ and 904 pg/m³ during one sampling period; indicating the possible use of the pesticide in the farm areas at that period.