Sulphur dioxide

Additional ecotoxological information

Administrative data

Endpoint:

additional ecotoxicological information

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

No guideline followed. There is no indication of the significance (p-values) for the individual measurements. Therefore it remains unclear at which SO2 concentrations significant effect occurs. However, using the data provided, it should be possible to calculate a preliminary EC10 (Unfortunately no raw data of the individual replica's are reported). Not a standard test species, non European test species.

Data source

Reference

Reference Type:

publication

Title:

Growth and stomatal conductance of Prosopis cineraria (ghaff tree) exposed to sulphur dioxide

Author:

S H Al-Rawahy, H Al-Amri, A Al-Hinai, N Sherwani.

Year:

2007

Bibliographic source:

Asian J. Plant Sci. 6, 673-677

Materials and methods

Test guideline

Qualifier:

no guideline followed

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Sulphur dioxide

EC Number:

231-195-2

EC Name:

Sulphur dioxide

Cas Number:

7446-09-5

Molecular formula:

SO2

IUPAC Name:

Sulphur dioxide generated from sulphur by combustion

Details on test material:

Source: MEGS Specialty Gases, Inc.)
- Physical state: gas

Results and discussion

Any other information on results incl. tables

There is no indication of the significance (p-values) for the individual doses. Therefore it remains unclear at which SO2 concentrations significant effect begins.

The formation of marginal necrotic areas on leaflets was seen as the first symptom of SO2 injury in P. cineraria plants. Leaf senescence was highly significant (p<0.01) in plants exposed to SO2 in light conditions and significant (p<0.05) in plants exposed to SO2 in dark conditions compared with control plants. There was significant (p<0.05) decrease in Relative Growth Rate per week in plants exposed to SO2 in both light and dark treatments compared with control plants, but more pronounced reduction in light conditions. Stomatal conductance was significantly (p<0.01) reduced after SO2 exposure in both light and dark treatments.

% effect at lowest dose (25 ppb):

1) At 25 ppb light conditions

Rel. growth weight per week reduced by 18%

Shoot dry wt reduced by 4%

root dry wt increased by 4%

Leaf area reduced by 20%

Steam diameter reduced by 8%

Leaf necrosis 18.3%

Dead plants: 4%

2) At 25 ppb dark conditions

Rel. growth weight per week reduced by 2%

Shoot dry wt reduced by 1%

root dry wt reduced by 1%

Leaf area reduced by 6%

Steam diameter reduced by -

Leaf necrosis 7.2%

Dead plants: 1%

Applicant's summary and conclusion

Executive summary:

The study aimed to investigate the sensitivity of an indigenous (Sultanate of Oman) leguminous plant species,Prosopis cineraria(ghaff tree), to SO2 pollutant. Plants were exposed to 0, 25, 50, 100 and 150 ppb SO2 for 30 min daily for the period of 10 weeks, under light and dark conditions. The formation of marginal necrotic areas on leaflets was seen as the first symptom of SO2 injury in P. cineraria plants. Leaf senescence was highly significant (p<0.01) in plants exposed to SO2 in light conditions and significant (p<0.05) in plants exposed to SO2 in dark conditions compared with control plants. There was significant (p<0.05) decrease in Relative Growth Rate per week in plants exposed to SO2 in both light and dark treatments compared with control plants, but more pronounced reduction in light conditions. Stomatal conductance was significantly (p<0.01) reduced after SO2 exposure in both light and dark treatments.