Lab Notes | On “dolomite beach” and the real public health challenge in Metro Manila

By Jose Antonio A. Montalban

Last year, Department of Environment and Natural Resources (DENR) Undersecretary Jonas Leones announced that by the end of 2021, swimming activities may already be allowed on Manila Bay’s dolomite beach [1], with its reiteration to achieve it at the end of January 2022 [2]. They stressed that the reduction of fecal coliforms in the area will determine the acceptability of the dolomite beach for swimming activities. [3-4]

Altogether, DENR and other supporters of the project are positive that ongoing so-called “nourishment” projects centered on the dolomite beach will soon make it safe for swimming, something that various organizations and individuals are strongly opposed to due to the perceived heedlessness of the Department in fully addressing the root cause of environmental pollution in Manila Bay.

We take a look at the real situation of the dolomite beach in relation to the real challenges of public health preservation in Metro Manila.

Fecal coliform as the sole parameter for water quality: is it enough?

Their point: As repeatedly mentioned, addressing fecal coliform in Manila Bay can make it “swimmable” again through its dolomite beach within the Baywalk area. [1-2]

Our point: Addressing fecal coliform alone is not enough to qualify Manila Bay as “swimmable”. There are other parameters that characterize the water quality of the Bay.

• Aside from being a primary parameter for water quality according to our national effluent standards [5], fecal coliform, while generally considered to be harmless, do serve as indicator species for pathogenic microorganisms thriving within the water sample. [6-7]
• Considering the urban landscape of Metro Manila as a mixture of residential, commercial, and industrial elements, there are other pollutants to consider aside from fecal coliforms, namely heavy metals, persistent organic pollutants (POPs) and other critically hazardous pollutants. These create more negative implications to public health than pathogenic microorganisms. [8]

Dolomite sand to reduce fecal coliform?

Their point: There were studies suggesting that dolomite sand can neutralize and filter fecal coliform bacteria as a material for water and wastewater treatment.

Our point: Not only that there are no approved claims that dolomite sand or aggregate can neutralize and filter fecal coliform bacteria for water and wastewater treatment, but dolomite as a foreshore sand can become a reservoir of coliform bacteria.

• The use of dolomite as a viricide and a sporicide can only be achieved through further changes in its overall composition (heat treatment in powder form). Thus, heated dolomite powder is generally used for medical applications. [9-10]
• There are studies that suggest the prevalence of coliform bacteria proliferation on foreshore sand. Therefore, this could also be true in the use of dolomite aggregates as foreshore sand on the Manila Baywalk beach area. Consequently, the continuous dumping of dolomite sand in Manila Bay without addressing the root cause of coliform contamination only creates a public health hazard. [11]

On addressing the real public health challenge in Metro Manila

It should be well emphasized that there is a direct correlation between addressing the root cause of environmental pollution in a society and addressing its negative outcomes towards public health [12]. However, this is not the case in DENR’s Manila Bay Rehabilitation Project.

Besides, there are other bigger environmental issues at hand that should be addressed first instead of the mere aesthetic beautification in the Baywalk area. The recent re-emergence of polio in the Philippines represents the need for a better infrastructure and framework for sanitation and pollution abatement systems. [13]

In addition, the emerging problem on antimicrobial resistance of pathogens brought by anthropogenic activities and sanitation malpractices have exacerbated the degree of environmental pollution in Metro Manila. This increases the need for a better sense of sanitation and pollution abatement infrastructure and framework, in order to lessen its impacts that will ultimately draw irreversible problems not only in Manila Bay as a receiving water body, but also to other water bodies within the country. [14-15]

Furthermore, there are a lot to be addressed in the existing framework of solid and hazardous waste management and diversion in Metro Manila and nearby provinces. The continuous contamination in Manila Bay has worsened the public health threat primarily in the marginalized sector, not to mention that solid waste are considered reservoirs for zoonotic, water-washed, and water-borne diseases. [16]

Conclusion

The constant call for the true rehabilitation and restoration of Manila Bay shall continue. Without addressing the root causes of point-source pollution in Metro Manila and nearby provinces, the supposed Manila Bay Rehabilitation Project will only be a waste of public funds and will consequently increase environmental degradation.

At the end of the day, the public health of Metro Manila should be the priority. We will continue to reiterate the same standpoint: dolomite sand is not the solution to Manila Bay’s pollution problem, nor will it help the people’s health, mental or otherwise.

References

1. “Swimming may be allowed in Manila dolomite beach – DENR”; The Philippine Star, October 19, 2021, https://www.philstar.com/nation/2021/10/19/2135081/swimming-may-be-allowed-manila-dolomite-beach-denr
2. “DENR targets swimmable dolomite beach this month”; The Philippine Star, January 2, 2022, https://www.philstar.com/headlines/2022/01/02/2151353/denr-targets-swimmable-dolomite-beach-month
3. “High coliform levels render Manila Bay unsafe for bathing”; DENR, January 2021, https://www.denr.gov.ph/index.php?id=832&page=89&sort=&filter=&searchword=
4. “EMB-NCR conducts ocular inspection of sampling sites and STP in Manila Bay”; DENR-EMB-NCR, October 14, 2021, https://ncr.emb.gov.ph/emb-ncr-conducts-ocular-inspection-of-sampling-sites-and-stp-at-manila-bay/
5. “Water Quality Guidelines and General Effluent Standards of 2016”; DENR, November 2016, https://emb.gov.ph/wp-content/uploads/2019/04/DAO-2016-08_WATER-QUALITY-GUIDELINES-AND-GENERAL-EFFLUENT-STANDARDS.pdf
6. “Indicators of microbial water quality”; World Health Organization (WHO), 2001, https://www.who.int/water_sanitation_health/dwq/iwachap13.pdf
7. “Coliform Bacteria: fact sheet”; Minnesota Health Department, July 2019, https://www.health.state.mn.us/communities/environment/water/docs/contaminants/coliform.pdf
8. “Environmental assessment of metal pollution in Manila Bay surface sediments”; Philippine Journal of Science, June 2019, https://philjournalsci.dost.gov.ph/images/pdf/special_issue/148_S1/environmental_assessment_of_metal_pollution_in_manila_bay_.pdf
9. “Antiviral activities of heated dolomite powder”; NCBI-NLM-USNIH, December 2008, https://pubmed.ncbi.nlm.nih.gov/19127652/
10. “Sporicidal characteristics of heated dolomite powder against Bacillus subtilis spores”; NCBI-NLM-USNIH, 2014, https://pubmed.ncbi.nlm.nih.gov/25252642/
11. “Foreshore sand as a source of Escherichia Coli in nearshore water of a Lake Michigan beach”; American Society for Microbiology, December 17, 2020, https://journals.asm.org/doi/10.1128/AEM.69.9.5555-5562.2003
12. “Environmental pollution and the global burden of disease”; British Medical Bulletin, December 2003, https://academic.oup.com/bmb/article/68/1/1/421204
13. “Polio case confirmed in the Philippines: DOH to mount mass immunization campaign”; Department of Health – Republic of the Philippines, September 19, 2019, https://doh.gov.ph/node/18012
14. “Antibiotic resistance and extended-spectrum beta-lactamase production of Escherichia coliisolated from irrigation waters in selected urban farms in Metro Manila, Philippines”; Multidisciplinary Digital Publishing Institute, April 2018, https://www.mdpi.com/2073-4441/10/5/548/htm
15. “Who possesses drug resistance genes in the aquatic environment?: sulfamethoxazole (SMX) resistance genes among the bacterial community in water environment of Metro-Manila, Philippines”; NCBI-NLM-USNIH, April 30, 2013, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3639423/
16. “Solid wastes provide breeding sites, burrows, and food for biological disease vectors, and urban zoonotic reservoirs: a call to action for solutions-based research”; Frontiers in Public Health, January 17, 2020, https://www.frontiersin.org/articles/10.3389/fpubh.2019.00405/full

About the author

Jose Antonio A. Montalban is a licensed sanitary engineer and a technical volunteer for Pro People Engineers and Leaders (PROPEL). He is involved in various engineering consultancy and design work for public health and sanitation systems, pollution abatement and environmental management. He has a bachelor’s degree in Environmental and Sanitary Engineering and is currently finishing his graduate studies on Environment and Natural Resources Management with its focus on Upland Resources.

Photo: MGB