Miljöpåverkan
Levotyroxin
Miljörisk:
Användning av levotyroxin har bedömts medföra försumbar risk för miljöpåverkan.
Nedbrytning:
Levotyroxin är potentiellt persistent.
Bioackumulering:
Levotyroxin har låg potential att bioackumuleras.
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Detaljerad miljöinformation
Environmental Risk Classification
Predicted Environmental Concentration (PEC)
PEC is calculated according to the following formula:
PEC (μg/L) = (A*109*(100-R))/(365*P*V*D*100) = 1.37*10-6*A*(100-R)
PEC = 0.0011μg/L
Where:
A = 7.78 kg (total sold amount API in Sweden year 2020, data from IQVIA).
R = 0% removal rate (due to loss by adsorption to sludge particles, by volatilization, hydrolysis or biodegradation) = 0 if no data is available.
P = number of inhabitants in Sweden = 1*107
V (L/day) = volume of wastewater per capita and day = 200 (ECHA default) (Ref.1)
D = factor for dilution of waste water by surface water flow = 10 (ECHA default) (Ref.1)
Predicted No Effect Concentration (PNEC)
Ecotoxicological studies:
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Algae (Pseudokirchneriella subcapitata):
EC50 = 520 mg/L after 72 hours exposure (guideline OECD 201) (Ref.2)
-
Crustacean - Fresh water flea (Daphnia magna):
EC50 = 497 mg/L after 72 hours exposure (guideline OECD 202) (Ref.2)
-
Fish - Sheepshed minnow (Cyprinodon variegatus variegatus):
LC50 > 1000 g/L after 72 hours exposure (modified OECD 203 Fish Acute Toxicity Test) (Ref.2)
PNEC = 497 µg/L (justification of chosen assessment factor)
PNEC (µg/L) = lowest EC50/1000 where 1000 is the assessment factor used. EC50 for Daphnia magna has been used as for this calculation since it is the most sensitive of the three tested species.
Environmental risk classification (PEC/PNEC ratio)
PEC/PNEC = 0.0011 µg/L / 497µg/L = 2.14 *10-6
PEC/PNEC < 0.1 which justifies the phrase ”Användning av läkemedlet har bedömts medföra försumbar risk för miljöpåverkan.”
Degradation
Test results from "closed bottle test" (guideline 301 D) shows that the biological degradation is 0% in 28 days.
Levothyroxine is potentially persistent.
Bioaccumulation
Partitioning coefficient:
Log Pow = 2,4 (Ref.3; computed by XLOGP3-AA method)
Since log Pow < 4, the substance has low potential for bioaccumulation
References
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ECHA, European Chemicals Agency. 2008 Guidance on information requirements and chemical safety assessment. http://guidance.echa.europa.eu/docs/guidance_document/information_requirements_en.htm
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Report: Test Results for the Test Substance Levothyroxinsodium (Report Nr: R 197–05), Nycomed AB
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United States National Library of Medicine, PubChem, Compound, Levothyroxine, http://pubchem.ncbi.nlm.nih.gov/. Accesses: 21 July 2015