Analysis of Arsenic levels in rice (Oryza sativa) and water samples from Barangay Lucnab, Baguio City, Philippines

Dr. Marilou M. Saong, ChE, LPT1 and Ivy May V. Marbella2

1 Faculty, School of Natural Sciences
University of Baguio, Baguio City, Philippines
2 Faculty, School of Natural Sciences
University of Baguio, Baguio City, Philippines


The World Health Organization considered arsenic as one of the ten chemicals of primary public health concern. Numerous pieces of evidence proved that rice and water, as part of the human diet, are potential sources of arsenic exposure among the majority of the populations around the world. Thus, this study determined the levels of As in rice and water samples from one of the adopted barangays of the University of Baguio, using Atomic Absorption Spectroscopy. The NFA rice samples had arsenic content below the detection limit, while the other rice samples had
arsenic ranging from 8 µg/L to 27 µg/L, with the lowest and highest values found in organic brown rice and white rice variety, respectively. Compared to the 150 µg/L MCL set by WHO, the values were significantly lower. Despite higher arsenic content in mixed rice than in white rice and organic colored rice, the mean differences are not significant, as proven by the Kruskal Wallis Test, 2 (2) = 5.22, and p=.074. All ten drinking water samples bought from water refilling stations had no detectable arsenic, while eight of the 18 (44%) of the spring water samples showed detectable amounts but are far below MCL of arsenic in drinking water. The low levels of arsenic detected in the 20 analyzed rice samples pose low health risks when consumed over a short period. However, since rice is part of the residents’ daily diet, higher health risks may be expected because of the heavy metal’s ability to bioaccumulate. The low amounts of arsenic in spring water samples posed no significant health risks associated with arsenic exposure. Despite this, the spring water’s high acidity may have leached other metal heavy ions which may pose health risks due to heavy metals’ proven toxicity when ingested in large amounts.

Keywords: Arsenic, rice, water samples, health risks, Baguio City