Acrylaldehyde

Bioaccumulation: terrestrial

Description of key information

Based on experimental results absorption of acrolein by terrestrial plants is poor. In pepper plants (Capsicum sp.) irrigated with water containing acrolein (0.25 and 0.5 mM), low values of acrolein were measured in all samples (18 µg/kg in fresh tissue 1 h post-treatment). The acrolein concentrations were reduced to undetectable levels within a few hours, giving a half-life of acrolein in pepper plants of 10.3 h, irrespective of the initial concentration of acrolein applied.
Lactuca sativa plants were exposed to one single and multiple applications up to 50 days of 14C-acrolein at 75 ppm in irrigation water. The results indicate that acrolein degrades very rapidly in lettuce. Although not identified, four metabolic products were observed using TLC analysis. The metabolic products were hydrolysable by HCl into many products, suggesting that they consist of multiple, conjugated polar metabolites of 14C-acrolein or biological components which have incorporated 14C-fragments resulting from further degradation of 14C-acrolein metabolites.

Additional information

1. European Union Risk Assessment Report of Acrolein (EU, 2001)

None

2. Agreement with further international Reports and Studies published after finalisation of the EU Risk Assessment Report 2001  

WHO (2002): Absorption of acrolein by terrestrial plants is poor.

3. Substantial disagreements in comparison to further international Reports to European Union Risk Assessment Report 2001

None

4. Additional aspects in further international Reports

None

5. Additional information in newer Studies, not included in the European Union Risk Assessment Report 2001 or further cited international reports

Pepper plants (Capsicum sp.) were irrigated with water containing acrolein (0.25 and 0.5 mM). 1 h post-treatment a minute concentration of acrolein (18 µg/kg fresh tissue) was detected in the plants. The maximum concentration of acrolein was measured in the samples taken on the first day post-treatment (48 µg/kg ft). At the second day post-treatment, the highest registered concentration of acrolein in plants (2 µg/kg ft) was measured in the 0.5 mM treatment. The low values of acrolein measured in all samples were reduced to undetectable levels within a few hours, giving a half-life of acrolein in pepper plants of 10.3 h, irrespective of the initial concentration of acrolein applied.

Lactuca sativa plants were exposed to one single and multiple applications (at day 0, 17, 34 and 50) of ¹⁴C-acrolein at 75 ppm in irrigation water. Plants were harvested after 0, 29 and 53 days (single application) and after 0, 17, 34, 51, 52 and 53 days (multiple applications).
The single application of acrolein at 75 ppm resulted in total radioactive residues (TRR) in leaves of 0.79 ppm (79% acrolein) 1 hr after application to 0.003 ppm (0.0% acrolein) 53 d post application. Corresponding values for the roots were 0.012 and 0.006 ppm, respectively.
Multiple applications of acrolein at 75 ppm resulted in TRR in leaves of approximately 1.10 ppm (91% acrolein) and 1.04 ppm (49% acrolein) 1 hr after the day 0 and day 50 treatments, respectively. This fell to 0.77 ppm on day 53 (0.0% acrolein). Corresponding values for the roots were 0.142, 0.05 and 0.09 ppm, respectively.
The results indicate that acrolein degrades very rapidly in lettuce. Although not identified, four metabolic products were observed using TLC analysis. They were hydrolysable by HCL into many products, suggesting that they consist of multiple, conjugated polar metabolites of 14C-acrolein or biological components which have incorporated 14C-fragments resulting from further degradation of 14C-acrolein metabolites.

6. Conclusions

Based on experimental results absorption of acrolein by terrestrial plants is poor. In pepper plants (Capsicum sp.) irrigated with water containing acrolein (0.25 and 0.5 mM), low values of acrolein were measured in all samples (18 µg/kg in fresh tissue 1 h post-treatment). The acrolein concentrations were reduced to undetectable levels within a few hours, giving a half-life of acrolein in pepper plants of 10.3 h, irrespective of the initial concentration of acrolein applied.

Lactuca sativa plants were exposed to one single and multiple applications up to 50 days of ¹⁴C-acrolein at 75 ppm in irrigation water. The results indicate that acrolein degrades very rapidly in lettuce. Although not identified, four metabolic products were observed using TLC analysis. The metabolic products were hydrolysable by HCl into many products, suggesting that they consist of multiple, conjugated polar metabolites of 14C-acrolein or biological components which have incorporated 14C-fragments resulting from further degradation of 14C-acrolein metabolites.