Description of the environmental risk
Environmental risk is connected to the production, management and distribution of goods, services or industrial products from the primary or secondary sector (agriculture and industry) as well as the tertiary sector (or services), which may represent the cause of accidents with short-term effects on public health.
Even if the change to physical-chemical parameters of the environment was caused by exceptional natural events, such as secondary volcanic phenomena, the environmental risk must be considered a mainly manmade risk.
While current legislation provides for a regime of ordinary management of environmental problems, it does not exclude recourse to emergency and special procedures should the health of the population resident in an area subject to the abovementioned risk come under threat.
In actual fact, many areas on national territory have experienced or are experiencing situations such as to require urgent prescriptive operations for the protection of public safety. In this sphere, the Department of Civil Protection is increasingly called upon to intervene, and is engaged in complex problems that range from waste to water pollution emergencies, electro smog, problems associated with asbestos use, even if such issues do not necessarily involve recourse to a state of emergency and the issue of civil protection orders.
The earth is covered by approximately one and a half billion cubic metres of water, 97% of which is salty seawater and the remaining 3% fresh water in the form of lakes, rivers and icebergs and groundwater. Water is usually thought of as an unlimited resource, divided into just two types, fresh and salty.
In reality, water can be distinguished on the basis of other characteristics:
• physical (temperature, colour, turbidity)
• chemical (salt, gas, chemical product content);
• biological (presence of micro organisms)
Polluting water means altering its characteristics in such a way as to make it unsuitable for the purpose it serves.
Types of water pollution
There are different types of water pollution:
• civil: derives from urban waste water that flows into rivers or directly into the sea without any purification treatment;
• industrial: formed by different substances that depend on industrial production;
• agricultural: linked to the excessive or improper use of fertilisers and pesticides, which, being generally water-soluble, penetrate the soil and pollute the groundwater.
Some chemical substances present in the water are particularly hazardous for human health and the survival of many living species, such as some metals (chrome, mercury) or compounds such as chlorinated solvents.
Causes of water pollution
Industrial waste contains a large quantity of pollutants and their composition varies according to the type of production process. Their impact on the environment is complex: toxic substances contained in this waste often mutually reinforce their damaging effects and so the total damage is greater than the sum of each single effect. Chemical fertilisers used in agriculture and sewage produced by animal farms are rich in organic substances which, washed away by the rain, leaches into the groundwater aquifers or into surface bodies of water. These substances are often joined by larger debris, which is deposited on the bottom of pools.