European environment and health

A report by the European Environmental Agency shows that as many as 60 000 deaths a year and 25-33% of diseases in industrialised European cities are caused by long-term exposure to air pollution, with children increasingly at risk to asthma and allergies triggered by bad air. To reverse this alarming trend, the European Commission launched, in June 2004, a strategy and action plan – European Environment and Health Strategy – to reduce diseases linked to environmental factors.

European research must provide key knowledge to better target and implement action and policy-making at EU and national level. The strategy – known by its acronym SCALE – is based on five key elements:

• Science – to broaden our perspective on the often very complex link between environment and health
• Children – since they are particularly vulnerable to environmental hazards
• Awareness-raising – so people know of the environmental-health problems and how they can be solved
• Legislation – EU regulations will complement national and international initiatives
• Evaluation – continual verification of how effective the strategy is in reducing known environment-related health problems and addressing new ones as they develop.

The strategy is being implemented in cycles. The first cycle, running from 2004-2010, is focusing on four health effects:

• Childhood respiratory diseases, asthma, allergies
• Neurodevelopment disorders
• Childhood cancer
• Endocrine disrupting effects

...wastewater gardens...

Pollution of water resources by improperly or inadequately treated domestic wastewater (sewage) contaminates drinking water supplies and so is a leading cause of human disease worldwide. Health problems related to sewage are widespread, ranging from children swimming in open sewage treatment ponds, failure of leachfields due to wet season inundation, and sewage effluent pollution of groundwater, rivers and lakes with adverse impact on drinking water quality and recreational use of these resources. Small, rural and isolated communities have great expense and difficulty in maintaining the highly technical systems that they are given. It is frequently reported that maintenance soon becomes almost non-existent and inadequate sewage treatment results.

In addition to issues of human health, the release of nutrients from this wastewater causes eutrophication in the environment, leading to a wide range of environmental problems. These include coral reef decline, oxygen depletion/fish kill and ecological degradation of rivers and lakes, and giving competitive advantage to weed species over native plants in ecosystems impacted by release of human wastewater.

The Ecotechnics invention uses simple but very effective design principles. Primary treatment, to separate solids, occurs in a conventional, watertight septic tank or settling lagoon. But then instead of passing directly into a leachfield, with its attendant problems of little further treatment, smell, clogging and large size, the nutrient-rich wastewater effluent is fed into a lined, two-cell, subsurface flow wetland. In this type of wetland the sewage water is kept 5-10 cm. below the surface of a bed (0.5 – 1 m deep) of gravel. The treatment compartments are planted with a wide variety of wetland plants, specially selected for the locality, into the gravel bed filled with sewage water. As entering effluent overflows the first stage cell, it passes to the second, and then to a comparatively small subsurface discharge or the treated water can be recycled for further irrigation of lawns, shrubs, flowers or trees. Wastewater is generally held in the wetland systems for 5-7 days.

There are many advantages of the ecological subsurface flow wetland approach include:

1) Fecal coliform bacteria are reduced more than 99% in the wetlands, without the use of expensive, environmentally harmful chemicals like chlorine. Biochemical oxygen demand (BOD) reduced 85-90% from influent levels, and removal of nitrogen and phosphorus is substantial.

2) The wetlands are low-cost, low-tech and long-lived. Maintenance requirements are simple.1

3) There is no malodor as the sewage is kept from contact with the air.

4) There are no mosquito-breeding or other nuisances associated with open wastewater (e.g. sewage lagoons or surface-flow wetlands).

5) The possibility of accidental public contact with the sewage reduced to someone deliberately digging into the wetland gravel.

6) Subsurface flow wetland systems are capable of extremely high rates of wastewater cleaning. In research over the past several decades, this type of wetland, even in its earlier design forms, has a well-documented track record of consistently cleaning water to levels better than municipal standards for wastewater treatment.

7) The intensity of treatment is such that only 1/5 the area is required compared to a surface-flow wetland. Every particle of gravel becomes colonized by the natural variety of microbes that are effective in utilizing and treating wastewater, and the root systems and water/nutrient uptake of the plants increase treatment efficiency.

8) Where higher treatment than normal municipal standards is required for special purposes, an increase in wetland area provides the equivalent of advanced water treatment.

9) Significantly less wastewater (35-70% depending on design) is discharged from these special wetlands, because the plants use large quantities of water in their transpiration.

10) Subsurface wetlands can be exactly sized from small units for a single residence to larger areas for small city/town systems and so no surplus capacity need be paid for than is needed. On the other hand, new demands can easily be met by simple unit expansion

11) The wetland systems add considerably to the landscape beauty in communities where they are used, and can also include plants to be harvested for useful or saleable products.
In Mexico, hotels and house-owners with wetland treatment systems are now vying for the most beautiful gardens.

The plants, specially selected for ecosystem fit and productivity, used in the subsurface flow wetland systems are key to their performance. Savannah Systems offers also either to contract for these plant assemblages, or to consult the gardener in charge or the owner of the area in which the system is installed. In addition to direct uptake of the nutrients contained in the sewage water, wetland plants act like oxygen-pumps, supplying their root systems with the aeration required for growth. In the process, the plants create micro-zones for aerobic bacteria to flourish. Thus, the wetland has both anaerobic and aerobic chemical reactions, which account for their high level of treatment of the wastewater.

The opportunities for beneficial and productive use of the wetland plants give a great range of choice to the user. The wetlands can be used for creating beautiful gardens and landscape diversity of home, hotel or town. The gardens can also feature productive plants, such as flowers for sale, fiber / fodder plants and timber trees. Plants harvested above the dry surface of the gravel pose no danger of wastewater contamination. Other opportunities include botanic garden displays, and for creating additional areas of wetland ecosystems, with rich biodiversity, wildlife and bird habitat, to compensate for the wetland loss elsewhere.

Applicability in Tropical Conditions. Since these systems rely on green plants and microbes, they perform even better in warm, sunny conditions than the successful wetland systems in cold climates such as Canada, Germany, the United Kingdom, and northern United States. In milder and especially tropical conditions with higher temperatures and increased sunlight, system effectiveness is high year-round. Thus, the approach seems ideal for mild-climate and tropical areas to serve remote communities, rural towns and houses. Subsurface flow wetlands are especially recommended for use in on-site systems for houses in areas with groundwater too close to the surface, such as often occurs during the wet season, and sites with rocky or impermeable clay soils that prevent standard leachfields from operating.

In detailed research conducted along the coast of the Yucatan, in southeastern Mexico, and critically checked by University of Florida scientists, to prevent pollution damage to off-shore coral reefs, 3-4 square metres of wetland per full-time resident proved capable of removing 85-90% of BOD, nitrogen and phosphorus, and fecal coliform was reduced 99.8+% without use of chemicals. Two Wetland Gardens totaling 130 square meters, served to treat the gray and blackwater of 40 residents, and supported 65-70 varieties of wetland plants. Biodiversity was three times greater than in adjoining natural mangrove wetlands, and only 5% less than in the inland tropical forest areas.

Pollutant induced diseases

Academic Department of Respiratory Medicine, St Bartholomew's and the Royal-London School of Medicine and Dentistry, London Chest Hospital, UK.

Evidence from both epidemiological and laboratory-based studies suggests that increased exposure to liquid petroleum and gas-derived air pollutants [nitrogen dioxide (NO2), ozone, and respirable particulate matter] may play a role in the clinical manifestation of both allergic and non-allergic airway disease. The mechanisms and cell types involved in pollutant-mediated effects in the airways, however, are not clear. In vitro studies have suggested that human fibroblasts, B-lymphocytes, alveolar macrophages, and epithelial cells/cell lines may be involved. Studies of fibroblasts and macrophages have demonstrated that exposure to ozone results in decreased cell viability and increased release of pro-inflammatory mediators from macrophages. Similarly, studies of B-lymphocytes have demonstrated that exposure to diesel exhaust particles (DEP) enhances the synthesis of immunoglobulin E by these cells. The airway epithelial cells have received the greatest attention in mechanistic studies of air pollution-induced airway disease and suggest that these cells are likely to play a pivotal role in the pathogenesis of airways disease. Various studies have demonstrated that exposure of nasal or bronchial epithelial cells to NO2, ozone, and DEP results in significant synthesis and release of pro-inflammatory mediators, including eicosanoids, cytokines, and adhesion molecules. Additionally, evidence suggests that epithelial cells of atopic individuals release significantly greater amounts of cytokines such as granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-6 (IL-6), IL-8, and regulated on activation, normal T-cell expressed and secreted (RANTES), on exposure to NO2 and ozone. Studies investigating the biological relevance of epithelial cell-derived pro-inflammatory mediators have shown that these enhance eosinophil chemotaxis and eosinophil adherence to endothelial cells, suggesting that pollution-induced inflammation of the airways is likely to be influenced by modulation of epithelial synthesis and release of these mediators.