BS EN ISO 15952:2011 pdf download.Soil quality — Effects of pollutants on juvenile land snails (Helicidae)— Determination of the effects on growth by soil contamination(ISO 15952:2006).
4 Principle
Juvenile land snails (usually Hefix aspersa aspersa MUller) are exposed during a period of 28 days to a test mixture containing the test substance. preparation or matrix at different concentrations. The test mixture is freshly prepared and renewed every 7 days.
According to the objectives. the test mixture may be prepared with artificial soil (6.3.2) or with a suitable natural soil (6.3.3).
The snails are ted dunng the test with uncontaminated food.
The effects on growth (fresh mass and shell diameter) and on survival are measured after 28 days of exposure (optionally, effects could be measured every 7 days during 28 days).
The results obtained during testing are compared with those of a control to determine the NOEC or LOEC and to allow the estimation of the concentration which reduces the growth of the snails by 50 % within 28 days with respect to the fresh mass [EC50,m (28 days)) and to the shell diameter (EC5O.d (28 days)) or other values of EC,
If the concentrations selected result In lethal effects. the results obtained during testing are compared with those of a control and used for estimating the concentration which causes the death ol 50 % of the snails (LC50(28 days)).
For parlicular applications, various parameters (ECu, NOEC, LOEC, LC50) can be assessed (optional) after exposure periods lower than 28 days (7 days, 14 days or 21 days).
The test is conducted in two stages:
- a preliminary test intended to indicate both the non-observed effect concentration, NOEC, and the complete growth inhibition. The resulting dose-response relationship is important for the proper design of the definitive test;
— a definitive test specifying the concentrations which cause between 10% and 90 % of growth inhibition. It is not necessary 10 perform a final test where the preliminary test has not revealed any inhibitory effects at the maximum concentration tested.
Juvenile land snails (usually Hefix aspersa aspersa MUller) are exposed during a period of 28 days to a test mixture containing the test substance. preparation or matrix at different concentrations. The test mixture is freshly prepared and renewed every 7 days.
According to the objectives. the test mixture may be prepared with artificial soil (6.3.2) or with a suitable natural soil (6.3.3).
The snails are ted dunng the test with uncontaminated food.
The effects on growth (fresh mass and shell diameter) and on survival are measured after 28 days of exposure (optionally, effects could be measured every 7 days during 28 days).
The results obtained during testing are compared with those of a control to determine the NOEC or LOEC and to allow the estimation of the concentration which reduces the growth of the snails by 50 % within 28 days with respect to the fresh mass [EC50,m (28 days)) and to the shell diameter (EC5O.d (28 days)) or other values of EC,
If the concentrations selected result In lethal effects. the results obtained during testing are compared with those of a control and used for estimating the concentration which causes the death ol 50 % of the snails (LC50(28 days)).
For parlicular applications, various parameters (ECu, NOEC, LOEC, LC50) can be assessed (optional) after exposure periods lower than 28 days (7 days, 14 days or 21 days).
The test is conducted in two stages:
- a preliminary test intended to indicate both the non-observed effect concentration, NOEC, and the complete growth inhibition. The resulting dose-response relationship is important for the proper design of the definitive test;
— a definitive test specifying the concentrations which cause between 10% and 90 % of growth inhibition. It is not necessary 10 perform a final test where the preliminary test has not revealed any inhibitory effects at the maximum concentration tested.
