Managing Environmental Risks to Food and Health Security in Asian Watersheds

This project combines the social, medical and physical sciences in order to develop strategies of ecological risk management for sustainable food, health security and watershed planning in the Laguna Lake region, the Philippines. In addition to the dense population and urbanization, the continuing deforestation, upsurge in inland fisheries, and unabated abuse of the land uses surrounding the lake have aggravated the deposition of the sediments and resulted in the rapid deterioration of water quality. Organized by Japanese and Filipino researchers, this project aims at critically examining resource degradation and pollution, its origin and effect on aquatic life, food production and quality, and subsequently on public health in the Laguna Lake watershed area.

Background and research objectives

This research project investigates the direct and complex links between environmental change, ecological degradation, food availability and quality, and human health. Research is conducted at three sites in the Laguna Lake region, a highly populated and variegated region in which rich ecological resources are threatened by rapid land use change, urbanization and industrialization. Study sites are representative of the challenges facing many other Asian watersheds.

The project has four principal objectives: 1) to document the current levels and pathways of heavy metals pollution in the aquatic resources of Laguna Lake; 2) to investigate the health condition of local residents and their perception of food risks; 3) to analyse the ecological effects of agrochemical inputs, and their cumulative impact on food production and relation to subsequent ecosystem deterioration; and 4) to describe land use change in the Laguna Lake area and its impact on material cycles directly related to agricultural productivity, such as sedimentation and groundwater level and quality.

Research organization

Five research teams are comprised mainly of researchers at RIHN, Yokohama National University and University of the Philippines; they work in collaboration with government agencies such as the Laguna Lake Development Authorities (LLDA) and local government units. The Environmental Risk Assessment Team identifies the exact sources of, and factors responsible for, particular pollutants in the food chain. The team uses stable isotope and other analytical techniques to investigate how land use change is associated with downstream pollution. The Socio-Economic Evaluation Team explores how market- and non-market-based instruments can be used to improve water quality, food security and public health. The Health Risk Evaluation Team describes human nutrition, history of disease, and life expectancy in the region, especially in relation to socio-economic dynamics. The Payment for Ecosystem Services Team (PES) investigates the design of ecosystem service payment programs that may support robust regional agroecologies. The GIS-based Risk Mapping Team supports the entire research project by creating a spatially-explicit database of key variables associated with risk in the food chain.

Figure 1  Basic Research Flow and Organization

Progress to date

Although research is still at an early stage of implementation, initial findings indicate that industrial and agricultural pollution is a major environmental issue in the region. Unsafe concentrations of heavy metals such as lead, chromium, cadmium, arsenic, and mercury have been found in the lake water column. Toxic concentrations of lead are now found in tilapia sampled in markets and caught in open water, as well as in some local crop plants such as kangkong (Ipomoea aquatica) and kamote (Ipomoea batatas). In quantity, however, most pollution is associated with untreated human waste; water-borne pathogens thus pose significant human health risk. Environmental degradation throughout the watershed has reduced resource availability to local residents. There is a danger of feedback cycles between resource deterioration and decreasing household income, access to food and public health. As a consequence, many households are exposed to health risks and food insecurity. Survey respondents, especially those dependent on fisheries and upland agriculture, reported significant concern for their ability to improve, protect and expand their current resource base.

The GIS team has begun spatial description of human and environmental health risks. Their database will allow integration and analysis of multivariate data, including resource presence and availability, community health and nutritional status, food availability and quality, and other factors affecting vulnerability to ecological risk. GIS analysis should also aid in identification of unforeseen transboundary risks associated with current and future land use changes in the target areas.

Figure 2  Transect Map of the Village PRA Sites	Figure 3  Participatory Rural Appraisal Activities

Figure 4  Extent of flood in the village of Applaya, Santa Rosa, Laguna

Plans for Full Research

The Environmental Risk Assessment Team takes a geochemical approach to the study of interactions between humans and nature. Using techniques of stable isotope analysis, it describes the pathways of multiple elements through water and soil environments. It also assesses water quality in relation to basic water quality criteria, trophic state parameters and phytoplankton communities, and aquatic macrophyte biosorption in order to address issues of stream turbidity, eutrophication and heavy metal pollution.

Socio-Economic Evaluation Team: (i) characterization of other critical watersheds surrounding Laguna Lake; (ii) food risk assessment; (iii) bio-economic modeling of the effects of land use patterns on lake water quality and commercial fish productivity; (iv) assessment of household and community vulnerability to environmental risks induced by changing land uses in the Dampalit Subwatershed, Los Baños.

The Health Risk Evaluation Team will continue with its baseline evaluation in order to clarify the type and severity of environmental exposure(s) affecting human health. It will describe community exposure to environmental pollutants near Laguna Lake and assess the health risks posed by consumption of fish and other local food products, such as shellfish and duck eggs, contaminated by heavy metals.

The PES Analysis Team will use municipality-level socio-economic statistics and/or interview data in order to examine the value of potential ecosystem services. It will also estimate the impact of different land use and policy options, from no conservation to full conservation, on farmer livelihoods.

The GIS-based Risk Mapping Team will enhance its ability to describe the benefits and risks associated with particular patterns of land use change, especially in relation to transboundary water-related disasters such as flooding, and to support development of comprehensive land use plans in selected municipalities in the region.

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