Currently used pesticides were regularly detected at ng/l-levels in rainwater in Sweden,

with maximum concentrations up to 0.8

μg/l for single compounds.

•

A total of 47 substances were detected, 26 of these being herbicides, 8 fungicides, 8

insecticides and 5 metabolites.

•

A significant contribution to atmospheric deposition in southern Sweden from pesticides

that are no longer registered for use within Sweden. Up to 18 different compounds

originating from outside of Sweden were detected, with eight of these occurring during all

four years.

•

Total seasonal deposition from currently used pesticides in southern Sweden ranged

between 300-1 000 mg/ha. Deposited amounts correspond to ca 0.01-0.0004% of applied

dose on Swedish fields.

•

Concentrations in rainfall exceeded occasionally the preliminary Swedish target values to

protect surface water quality for five of the pesticides.

•

There is a correlation between origin of air-masses and composition of detected

pesticides.

•

The concentrations of lindane, now banned within the EU, are decreasing as compared to

the beginning of the 1990s.

Recommendations for future work:

* Additional monitoring sites

A single monitoring site presents uncertainties in the actual deposition loads and of how

representative they are for larger regions, including a south-north gradient.

* A longer sampling season

The current monitoring program is limited to a four-month period. However, the application

season starts earlier and ends later in Continental Europe than in Sweden, including many

volatile fungicides and insecticides being applied during the summer months, e.g. in fruit

orchards and wines, when no collection of deposition is done in the current programme. It

would also be beneficial for the interpretations if more samples could be taken and with a

higher frequency.

* Inclusion of additional pesticides

To select additional pesticides based on their intrinsic properties (mainly vapour pressure,

half-life in air and persistence) and used amounts in Europe (the review also suggesting

pesticides that could be excluded from the analytical list). There are some 400 different

pesticides applied throughout Europe. The least investigated environmental fate processes

today is atmospheric transport. Little is known of atmospheric half-lives and degradation

processes in the air.

* Air sampling

A programme that also included air (gas and particle phase) sampling and dry deposition

would give information on transport mechanisms.