Page 183 - Materials Chemistry, Second Edition

168 LIFE CYCLE ASSESSMENT HANDBOOK

In a review of wine LCA studies, Petti et al. (Petti, et al. 2010) stated that one
of the problems encountered by most of the analysed studies was the difficulty
in finding specific data and characterisation factors for plant protection prod-
ucts and fertilizers used in the agricultural phase. As a consequence, an esti-
mation of nutrients or pesticides releases through different dispersion models
or assumptions was made. Margni et al. (Margni, et ah 2002) stated that the
assessment of the impact of pesticides on human health and ecosystem pres-
ents a certain degree of uncertainty as most of them, when used in agriculture,
can be harmful for organisms which are not directly targeted, thus contaminat-
ing land and aquifers, and creating a risk for the population. Furthermore, the
authors state that the impact of a pesticide depends on its interaction with the
environment, its toxicity and quantity used.
To better understand the implications arising from the use of data on pesti-
cides, the fate and behavior of pesticides in the environment must be known.
The application of a herbicide or an insecticide may have different destina-
tions: plants, air, soil, water and, indirectly, the terrestrial and aquatic wildlife
and man. The environmental dispersion processes are surface runoff, leaching,
volatilization, degradation and adsorption and desorption of pesticides in soil.
The plants constitute the primary object of the treatments; the absorption of
the pesticide by plants can be substantial. In applications of well-developed
vegetation, for example, it can be intercepted and subsequently taken up to
fifty percent of the amount of product used.
The air is simply a means of transport which the pesticide needs to reach the
target. The phenomena concerning the passage of the pesticide through the air
are the volatilization and drift. The volatilization of the pesticide is a transition
to a vapor by sublimation and evaporation and depends largely on the nature
of the compound and temperature. The drift is quite simply the physical trans-
port of the pesticide or a part thereof at a point away from the application,
mainly caused by the presence of wind during the distribution of the product
and when treatments are carried out on the edge of the plot.
Most of the pesticide applied flows on the ground; pesticides in soil fol-
low different paths depending on the complex interactions that are created
between pesticide, soil, plants and weather conditions. The factors that most
influence pesticide degradation into soil are represented by the physical and
chemical properties of the product, the type and amount of microorganisms in
the soil, moisture and soil temperature.
As with the soil, water can also be subject to receiving pesticide emissions.
Pesticides can get to it through events such as meteoric run-off or leaching.
In water bodies external to the agricultural land, contamination is mainly
linked to the surface run-off. The percolation instead is due mainly to pre-
cipitation after application on the plants; the portion of the pesticide that is
not absorbed by plants is in fact removed from their surface and ends in the
ground. Pesticides move into the soil in various ways, among which the most
important is the transportation in solution with water. The relative impor-
tance of each transport mechanism depends on the properties of pesticides,
the amount of rainfall and chemical and physical characteristics of the soil. As