Organochlorine Pesticide Residues in Surface Water and Groundwater Along Pampanga River, Philippines

Pesticide use in developing countries such as the Philippines has significantly increased food production. However, the improper and poorly regulated practice of pesticide use may lead to pollution of water resources. To detect and assess the extent of pesticide contamination, residues of organochlorine pesticides were tested in surface water and groundwater in selected areas along the Pampanga River, Philippines. The physicochemical properties of the surface water and ground water were also analyzed and results revealed that phosphate concentrations in surface water and groundwater samples were two to three times higher than the regulatory limits of 0.5 mg L−1, whereas the nitrate concentrations were below the regulatory limit of 7 mg L−1. Results further revealed that surface water and groundwater showed the presence of seven organochlorine pesticides and residues listed in the Stockholm Convention list of 2009 such as dieldrin, endrin aldehyde, α-BHC, β-BHC, δ-BHC, γ-chlordane, and endosulfan II. The concentrations of organochlorine pesticides including endrin aldehyde, total BHCs (i.e., α-BHC, β-BHC, δ-BHC), and heptachlor in groundwater were also found to exceed regulatory limits, indicating that these chemicals are still being used illegally and remains a major environmental concern despite the bans and restrictions. We suggest that routine chemical monitoring (including seasonal variations) coupled with biological monitoring using a battery of biomarker tests of organochlorine pesticide and residues along the Pampanga River is necessary to provide inputs for the control and reduction of environmental pollution and for minimizing human health risks

Land use and water quality assessment of some lakes in San Pablo City, Laguna, Philippines

Land conversions brought about by increasing population and the apparent increase of agricultural, residential, and commercial activities in San Pablo City have affected the quality of the water resources in the area. Agriculture and built-up areas comprised the majority of land use. Their assessment generated new interpretative maps after integrating remotely sensed data such as Landsat image and aerial photographs to various land use studies and surveys. The degradation of surface water quality was manifested by the physico-chemical analyses of sediments deposited in selected rivers and lakes. Sediments are considered as important source of information regarding water quality and chemical composition of water bodies. Sediments from Palacpaquen Lake and its adjoining rivers were assessed. The sulfate values of samples taken from different sites range from 47.79 ppm to 292.29 ppm, phosphates from 0.79 ppm to 5.53 ppm, nitrates from 146.98 ppm to 370.50 ppm, and organic carbon from 0.98 ppm to 4.56 ppm. The observed variability of nutrient concentrations were attributed mainly to anthropogenic activities around the lake and rivers which include agriculture, domestic and aquaculture. Land use has also affected groundwater resources, being one of the principal sources of drinking water. Untreated spring and well water are vulnerable to industrial, domestic, and agricultural pollution. Spring and well water from selected lakes such as Sampaloc, Mohicap, and Palacpaquen were monitored for total and fecal coliform contamination levels. There were varied levels of contamination. In most cases, the microbiological water quality in the sampled sites did not pass the drinking water standards of the Department of Health and the Department of Environment and Natural Resources. Proper land and water resource planning and management should be implemented to address the water quality degradation in San Pablo City

Phytoplankton composition and diversity in response to abiotic factors in Lake Buhi, Camarines Sur, Philippines

Phytoplankton were collected from eight sampling stations around Lake Buhi (Camarines Sur, Philippines) in September and November 2013. The eight sites represented varied zonation and resource uses. A total of 29 species were identified belonging to five major taxonomic groups: the diatoms (Heterokontophyta), green algae (Chlorophyta), cyanobacteria (Cyanophyta), eustigmatophytes (Heterokontophyta) and dinoflagellates (Dinophyta). Diatoms were the most abundant group (50%), followed by the green algae (41%). Sampling station with high concentration of fish pens generated high diversity (Shannon-Wiener diversity index 2.65) with dominance of pollution tolerant taxa, while the site near the outlet of the lake has the highest phytoplankton abundance (0.139 cells/ml). Results revealed significant differences in relative abundance of phytoplankton among sampling sites and between sampling months within each site. These differences were attributed to the variation in physico-chemical parameters among the sites. Canonical Correspondence Analysis (CCA) showed that nitrate, depth and turbidity positively influenced phytoplankton abundance. Variation in the abiotic factors, including resource use, affected spatial and temporal distribution of the phytoplankton community. Remediation measures on the lake must be directed towards the primary sources of these variations

Comparative Study of the Ecotoxicological and Histopathological Impacts of Effluent, Sludge Water, and Commonly Used Inorganic Fertilizers on Juvenile Oreochromis niloticus (Linnaeus, 1758)

Wastewater treatment systems, designed to treat domestic wastes, produce effluents and sludge that are high in organic matter and nutrient content. These effluents and sludge are now being used as organic fertilizers because such nutrients and organic matter are vital to plant growth. However, without proper treatment, these substances may eventually find their way into bodies of water through run off and/or infiltration with potentially dangerous consequences. This study, therefore, investigated the potential toxic effects of effluents and sludge produced from wastewater treatment facilities against commonly used inorganic fertilizers to an aquatic species. Toxicity tests (expressed as mean 96-hr LC50 in mg/L) and histopathological examinations of the liver were conducted using juvenile Oreochromis niloticus (Linnaeus, 1758) exposed to varying concentrations of effluent, sludge, and inorganic fertilizers (i.e., urea and complete fertilizer) to assess both acute and sublethal effects. The results of the acute toxicity tests show concentrations (expressed as mean 96-hr LC50 in mg/L or ppm) arranged in decreasing order of toxicity to tilapia: complete fertilizer 14-14-14 (1,396 ppm) \u3e urea (16,152 ppm) \u3e sludge (145,900 ppm) \u3e effluent (465,000 ppm). Histopathological examinations of liver tissues showed that exposure to the two inorganic fertilizers resulted to blood congestion and degeneration in comparison to those exposed to the sludge. Furthermore, results for fishes exposed to the lowest concentrations of the effluent also showed alterations in the liver tissue. These results demonstrate that the sludge and effluent are less toxic by several orders of magnitude than the inorganic fertilizers. It is suggested that further chronic toxicity and histopathological studies be done to determine their long-term impacts to receiving aquatic organisms to establish their potential for agricultural applications

Efficiency of Combined Co-composting, Vermicomposting, and Drying in the Treatment of Cadmium, Mercury, Helminths, and Coliforms in Sludge from Wastewater Facilities for Potential Agricultural Applications

Sludge generated from wastewater treatment facilities has been applied in agriculture as soil conditioners. However, the incomplete and/or inappropriate treatment of wastewater may result in sludge that may still contain heavy metals, helminth ova, and coliforms posing a risk to both humans and the environment. This study assessed various pretreatment techniques such as co-composting, vermicomposting, and a combination of these on sludge samples to remove heavy metals (cadmium and mercury), helminth ova, and coliforms. Physico-chemical and biological analyses were used to compare untreated (i.e. raw) and treated sludge samples. The results showed that for the raw sludge, mercury (4.02 +/– 0.17 mg/kg) and cadmium (6.30 +/– 0.48 mg/kg) exceeded the limits specified under the Philippine National Standard (PNS) for Organic Soil Amendments of 2 mg/kg and 5 mg/kg, respectively. Laboratory examinations also revealed the presence of helminth ova (5 ova/g) and coliforms (10 CFU/g) in the samples. Sludge samples subjected to a combination of co-composting and vermicomposting resulted in the elimination of mercury and a significant reduction in cadmium concentration from 6.30 mg/kg to 1.12 mg/kg. No helminth ova were observed in the samples after further drying. However, both treated and untreated sludge samples had low nutrient content. The study highlights the need for raising public awareness and educating farmers on the potential risks associated with the use of raw sludge for agriculture