Environmental issues and Phosphate Use

Environmental Issues

Among environmental issues raised in connection in phosphate fertilizer use, cadmium concentration has drawn much attention, but strictly in Western Europe.

The possible impact of fertilizer cadmium on the environment has been subject to a large number of scientific and technical contributions to knowledge about the "Cadmium Issue" in relation to the use of phosphate fertilizers in agriculture.

It is important to recall here that for the past several years, IMPHOS has been able to make considerable progress towards the advancement of scientific and technical knowledge about Cd, through organization of workshops, publication of papers, conduct of scientific, and technical desk studies, holding of several meetings and supplying relevant information to different Directorate Generals of the European Commission.

During 2005, IMPHOS strengthened these activities and concluded an agreement with the European Public Policy Advisors (EPPA). By virtue of this agreement, this Agency is charged with monitoring the cadmium issues at various levels in the appropriate Directorates General of the European Commission. EPPA is arguing for more scientific studies leading to indisputable evidence in the preparation of a proposal for a regulation of cadmium in the phosphate fertilizers.

Considering the above, IMPHOS main activities in this area during 2005 can be summarized as follows:
IMPHOS expressed its position on this regulation proposal in letters addressed to DG Enterprise, by arguing:

• Any measures adopted must be entirely based on an appropriate analysis of risks to health and the environment from Cd in fertilizers.

• Therefore, a risk analysis must take into account all variables including, sources of Cd emissions, varying soil and climatic conditions as well as soil use and output in all EU Member States. This statement falls in line with the recommendations made by the Scientific Committee on Toxicity, Ecotoxicity and the Environment (CSTEE), in its opinion to DG Enterprise on a limit value for Cd in fertilizers.

• The issue of a European Regulation on Cd may prompt similar regulations in other regions, including those still struggling to develop agriculture to achieve food security.

In pursuit of solutions for the Cd in fertilizers, IMPHOS met DG Enterprise in June, 2005 and emphasized its position on the Cd issue and its willing and availability to work with DG Enterprise, in search of mutually acceptable solution.

In addition, IMPHOS met DG Agriculture and DG Trade and conveyed to them the same message communicated to DG Enterprise.

Furthermore, IMPHOS addressed letters to DG Agriculture and DG Trade to convey mainly information about a study on the use of phosphate rock as a source of mineral feed supplements to cattle diet in Senegal and the main CSTEE (Scientific Committee for Toxicity, Ecotoxicity and Environment) opinions concerning the Risk Assessment Report on Cadmium.

It shows that:

First, the negative effects of phosphorus and calcium deficiencies can be overcome by supplementing cattle with phosphate rocks as sources of calcium and phosphorus. This mineral supplement resulted in many gains in meat production and cattle reproduction.

Second, a set of information related to the opinion of CSTEE, mainly stressed that:

• A limit of Cd in fertilizers should be derived based on risk assessment approach, and take all Cd sources into account.

The numerous IMPHOS activities dealing with this issue are considered significant contributions leading to the current situation manifested in the approach and decisions of DG Enterprise on cadmium in fertilizers.

Prospects for Other Uses of Phosphate Products

IMPHOS is in the process of considering new applications of phosphorus compounds other than fertilizers. These include data processing, energy, health, food preservation and environment protection. Among potential applications with very high added value, the following are attracting the interest of the Institute:

• New Titanium Oxy phosphate Material for Lithium Batteries. Application: Mobile phones, laptops.
• Composite Membranes of Bacterial cellulose and sodium polyphosphate. Applications: medical applications, dietary fibres, headphone membranes, special paper, protective layer in the construction of enzyme-based glucose sensors, fuel cells, etc.
• CdS and WO3 (tungsten oxide) nanoparticles in Eu3+ doped polyphosphate glasses. Application: Semiconduc-tor doped glasses.
• Development of Phosphate Crystalline Materials for Radioactive Wastes Solidification Towards Increasing the Ecological Safety of their Storage and Disposal. Application: The wide isomorphism of cation, including those which might be presented in various combinations and quantitative ratios in wastes of the nuclear fuel cycles.
• Effective Cellular Responses on Polarized Hydroxyapatites Vector Ceramics in Body Fluids. Application: Medical application, the Hydroxyapatites (Ca10(PO4)6(OH)2;HA) has an excellent biocompability and valuable electric properties.
• Pd2P2O7 and AuPO4 - New Anhydrous phosphates of Noble Metals. Application: Anhydrous Phosphorus can play the role of noble metal collectors, as: Gold, palladium and platinum.
• Ammonium polyphosphate - a multiuse Flame Retardant: New Developments and applications. Application: coatings, thermoplastics, thermo set resin and textile treatment.
• Convenient Syntheses and Physical Properties of Various Cyclo-Decaphosphates. Application: Water treatment.
• Alkaline Polyphosphates. Application: Food preservation.
• Hard Polymer Compounds of Polyorganophospha-zenes. Application: Substitute of silicone for medical application, Polymers used at high temperature for industrial application.

In addition, the Institute is assessing the significance of a number of other applications, including:

1. Food applications (French fries, vegetables, beverages, cereal products, egg products, fats and oils, noodles, toothpaste, etc.),

2. Technical applications (phosphate in detergents, softening and complexing agent, emulsifying agent, dispersing agent, buffer capacity, alkalizing capacity, etc.)

3. Metal treatment (cars, refrigerators, washing machines and several other painted or enamelled items),

4. Water treatment (polyphosphates can sequester the calcium and magnesium ions in soluble compounds),

5. Other applications such as ceramics enamels and refractory, porcelain, flame retardants, paints, glass, antifreeze agents, polystyrene, yeast and fermentation, etc.