CANDELARIA, Zambales – Demand for critical minerals continues to boom, but mining these comes with considerable environmental cost particularly regarding pollution of water sources.
From initiatory extraction of minerals to processing and even eventual termination of operations, the potential for contaminating water is pervasive, and irrespective of minerals being extracted, mining operations disrupt horological cycles while also introducing a range of pollutants into nearby water bodies.
Any physical act of mining, whether involving underground or surface extraction, inevitably disturbs any community’s surface. Such disturbance results to soil erosion while quantities of sediment are deposited into rivers and streams.
This sediment degrades water quality by multiplying turbidity thus reducing light penetration, destroys aquatic habitat resulting to damage in food chain and lessening reproduction of many species.
More acutely, sedimentation exacerbates flooding by reducing exit capacity of watercourses.
Such is now the case occurring in San Vicente River and Alindayat Lake in Zambales Province, about 117. 14 kilometers from Baguio City. They are now being impacted by heavy metals released through mining activities.
Metal pollution on soil possesses grave danger to the environment mainly due to the increasing amount of metal ions in the soil beyond the accepted standard level. High metal ions in soil causes blockage of some essential functional groups, and additionally, it may bind to biomolecules and change its transformation.
San Vicente River and Alindayat Lake are situated on the western side of Luzon along the West Philippine Sea (WPS) which China wants to grab from Philippine sovereignty.
Researchers Kathrina M. Villar, Gella P. Abella, Daryl A. Juganas, Maritta P. Valera, John Wayne A. Villen and Carl Dionello B. Ponce of Central Luzon State University (CLSU) in Munoz, Nueva Ecija conducted a study on the water bodies being compromised with heavy metal contamination.
Their study titled “Mangroves and Their Associates in Metal-Rich Soils in Candelaria, Zambales, Philippines,” has been accepted by the University of the Philippines, Los Banos, for publication in its distinguished UP Los Banos Journal of Environmental Science and Management.
As explained by the researchers, heavy metals released by mining activities like arsenic, cadmium, copper, lead, mercury and zinc are naturally present in ore deposits and surrounding rocks.
During excavation, these metals are freed by water and infiltrate groundwater through seepage. It accumulates as sediments, affecting water and living organisms leading to chronic toxicity of the food chain.
Exposure from these heavy metals causes a variety of health problems ranging from developmental issues, organ damage and in severe cases, like cancer.
On the other hand, acid mine drainage is considered the most notorious form of mining-related water pollution resulting from corrosion of sulfide minerals commonly found in ore deposits. When these minerals are exposed to air and water during mining activities, they react to form sulfuric acid.
This acid seeps into groundwater and the results to health are devastating.
In the municipality of Candelaria, Zambales, residents rely heavily on mangroves. These special coastal forests help protect the municipality from severe tropical storm, coastal erosion and fishing as the mangroves serve as important habitat for all marine species.
Mangroves are extremely important to the coastal ecosystems in Zambales where these certain shrubs and trees inhabit. Physically, they serve as a buffer between marine and terrestrial communities, protecting shorelines from waves, winds and floods.
In Zambales, the mangroves provide habitat for a diverse array of terrestrial organisms and many species of coastal and offshore fish and shellfish rely exclusively on these mangroves as their breeding, spawning and hatching grounds.
Mangrove thickets improve water quality by filtering pollutants and trapping sediments from the land and they reduce coastal erosion.
Such a relation exhibits the importance of mangrove conservation among the residents as they depend on the health of the forests.
However, this relationship is being rent apart by several environmental challenges that have led to deterioration of water and sediment qualities and are now compromising the health of San Vicente River and Alindayat Lake, hence affecting the well-being of people in Candelaria.
San Vicente River and Alindayat Lake are suffering from contamination of heavy metals, the study by the researchers of CLSU proved. Not only that. The long conducted study also determined through soil tests analysis that various sites in the mangrove ecosystem in Candelaria “revealed alarming levels of heavy metals, too, confirming finding of previous studies.”
For backgrounders, mining in Zambales began in 1933 of chromite ore that was extracted from Acoje Mines where many tribal males from Cordillera trooped there for employment. Four years later, the mines at Coto, Masinloc was opened.
Then other mines followed suit. Today, there are about 28 mines digging for aluminum, copper, calcium, chromite, cobalt and chromium in the province.
General patterns seen in similar environments throughout Zambales revealed the existence of mangrove areas of different species. In San Vicente River and Alindayat Lake, there are 20 mangrove species which belong to 11 different families and 11 mangrove-associated species belonging to 10 families.
River banks of San Vicente River are generally occupied by the Avicennia-Sonneratia-Rhizophora species, followed by the Bruguiera-Lumnitzera-Ceriops on the middle zone from the river bank to the landward side and the Excoecaria-Acrostichum-Heriteira-Nypa on the landward side of the river.
The study found heavy metals in the mangrove sediment exceeding the reporting limit set by the United States Environmental Protection Agency (USEPA), Conservation effort must be considered knowing that the area is contaminated with heavy metals and negatively impacting the quality and health of the ecosystem, the study stressed.
A recommendation by the researchers dwelt on assessment and heavy metal analysis to be conducted on a regular basis for the aquatic fauna along and within the mangrove areas of the two water enclaves.
Findings reveal that heavy metals such as nickel, chromite and chromium are the main pollutants of the river and lake studied. Although mangroves can help reduce heavy metal pollution, it nonetheless impacts the quality and health of this certain ecosystem, the researchers explained.
Notably, “The high concentration of heavy metals in the sediments of San Vicente and Alindayat Lake in Zambales may negatively impact the diversity of mangrove species,” The researchers stressed.
Heavy metals can alter the health of the soil and reduce its fertility and harm organisms leading to decline in mangrove species diversity, as these accumulate in roots of mangrove plants thus affecting their survival.
Additionally, the presence of heavy metals in mangrove sediments is a matter of concern because the mangrove system is home to several animal species consumed by people in Zambales.
The findings of the study provide the current heavy metal pollution occurring in Candelaria. But elsewhere in other parts of Zambales, rural communities have awakened to the fact that environmental destruction continues in their province due to mining.
For example, in the town of Santa Cruz, residents there made a plea through a petition for the court to grant their community an Environmental Protection Order (EPO) to stop nickel mining in their midst. Unfortunately, the plea of the petitioners was not granted.
A separate study conducted earlier by Ramon Magsaysay Technological University, in Iba, Zambales, revealed soils in three barangays Santa Cruz are no longer fit for agricultural use due to high concentration of nickel and chromium, making them unproductive an incapable to sustain plant growth.
Based on quantitative data gathered, the heavy metal concentration in the three barangays in Santa Cruz exceeded allowable metal concentrations proposed by WHO and FAO, the excess concentration inhibiting crop growth.
Furthermore, all rice and vegetable crops grown in said barangays showed physical changes such as leaf coloration and the leaves showing necrosis, or death.
Dark spots were seen on both primary and secondary veins of the leaves. There was a decrease in growth performance and attributed to the presence of nickel and chromium in the plant bodies.
It was also found by researchers of Ramon Magsaysay Technological University that there was a negative correlation of heavy metal presence on the crops to attain the right plant height and root length.
While nickel and chromium are essential to plants, the researchers contended that excessive amounts also lead to plant demise as these cause plant retardation and growth performance. Heavy metal concentration alters metabolic processes of plants and composition of cellular membranes of cells and cellular organelles.
An assessment of heavy metals in agricultural crops near mining areas in Zambales showed that nickel and chromium concentration in both pre and post assessment areas were higher than the accepted standard limit set by the Food and Agricultural Organization (FAO) and World Health Organization (WHO).
The researchers highly recommended that rehabilitation and mitigation on concentration of heavy metals be implemented in strategic areas in Zambales.
They also recommended that people continue to be vigilant and carefully scrutinize vegetable crops sold at the public markets to ascertain these crops have not been grown in parcels of land with heavy metal concentration.
