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Toxicological information

Repeated dose toxicity: inhalation

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Administrative data

Endpoint:
short-term repeated dose toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Reasonably well-documented paper. However, study results are not relevant since the Sr speciation (important in read-acrossability) is not given. Also competitive metals as calcium, magnesium were present. The concentrations in Sr in the fly-ash were not determined.

Data source

Reference
Reference Type:
publication
Title:
Distribution of metals of inhaled fly ash in various organs of rats at various periods after exposure.
Author:
Srivastava, V.K., et al.
Year:
1984
Bibliographic source:
J. Environ. Sci. Health, A19, 663-677

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The rats were exposed daily to fly ash in an inhalation chamber for 6 hours/d continuously for 15 days. The dust concentration in the chamber was maintained between 0.2 to 0.4 mg/L. Control rats were kept in a dust-free room. Records of their body weights were maintained. Rats of control and experimental groups were sacrificed by decapitation on 1, 7, 15 and 30 days after the last exposure. Before sacrifice, blood was collected from the jugular vein. After sacrifice, lung, liver, heart, kidney, and small intestine was collected, cleaned, wiped, weighed and processed for quantification of metals by atomic absorption spectrophotometry. Serum was also processed likewise.
GLP compliance:
not specified
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
not specified
Details on test material:
- Name of test material (as cited in study report): Strontium (fly ash)

Test animals

Species:
rat
Strain:
Wistar
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: from the institute maintaine dcolony (Department of Biochemistry, V.P. Chest Institute, Univercity of Delhi)
- Weight at study initiation: 170-175 g bw
- Diet (ad libitum): Hind Lever diet (Hindustan Lever Ltd., Bombay)
- Water (ad libitum): free access before and after exposure

No further information given.

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
not specified
Vehicle:
other: unchanged (no vehicle)
Details on inhalation exposure:
- rats were exposed in an inhalation chamber (624 liters capacity)
- The fly ash was collected from electrostatic precipitator of the IP Thermal power Plant New Dehli, using low sulfur pulverized coal during its operation.
- To remove coarser particles fly ash sample was sieved through 400 mesh sieve and this sieved material was used for inhalation studies.
- The approximate particle size of fly ash was determined using a light microscope fitted with an eyepiece graticule. This method could give an over estimate of particle size.
- The fly ash aerosol was generated by a Wright dust geneator and the dust cloud passed through alarge glass vessel, before entering the inhalation chamber.
- The dust concentration in the chamber was maintained between 0.2 to 0.4 mg/liter.
- Control rats were kept in a dust free room.

No further information given.
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
15 days
Frequency of treatment:
6 hours/d , daily
Doses / concentrations
Remarks:
Doses / Concentrations:
between 0.2 - 0.4 mg/L
Basis:
no data
No. of animals per sex per dose:
6 rats in each group analysed at each sacrifice period
Control animals:
yes

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: No data

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: Records of the body weights were maintained.

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data No data

WATER CONSUMPTION: No data

OPHTHALMOSCOPIC EXAMINATION: No data

HAEMATOLOGY: No data

CLINICAL CHEMISTRY: No data

URINALYSIS: No data

NEUROBEHAVIOURAL EXAMINATION: No data

OTHER:
- Before sacrifice, blood was collected from the jugular vein for serum preparation. serum was processed for quantification of metals by atomic absorption spectrophotometry.
- After sacrifice, lung, liver, heart, kidney, and small intestine was collected, cleaned, wiped, weighed and processed for quantification of metals by atomic absorption spectrophotometry.
-The following metals of fly ash were analyzed: Na, K, Fe, Ca, Mg, Pb, Zn, Cu, Co, Ni, Cr, Mn and Sr.
- Their distribution in lung, liver, heart, kidney, small intestine and serum was studied.
Sacrifice and pathology:
- Rats of control and experimental groups were sacrificed by decapitation on 1, 7, 15 and 30 days after the last exposure.
GROSS PATHOLOGY: No data
HISTOPATHOLOGY: No data

Results and discussion

Results of examinations

Details on results:
OTHER FINDINGS
- The results showed a profound increase in the concentration of Na, K, Fe, Ca, Mg, Pb, Zn, Cu, Co, Ni, Cr, Mn and Sr in serum of rats which inhaled fly ash.
- The results showed a profound increase in the concentration of Na, K, Fe, Ca, Mg, Pb, Zn, Cu, Co, Ni, Cr, Mn and Sr in all tissues of rats which inhaled fly ash.
- The increased levels of the metals were highest one day after the last exposure and at later periods their concentration declined which varied from metal to metal and from organ to organ.
- The Sr contents in all tissues were the lowest of all metals studied (0.2±0.1 to 0.3±0.1 µg/g wet tissue).
- The values tended to be higher at 1, 7 and 15 days.
- After 30 days, the fly ash Sr load from lung, liver, heart, kidney and small intestine was cleared to values of the control group.

Effect levels

Dose descriptor:
NOAEC
Remarks on result:
not determinable
Remarks:
no NOAEC identified

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
The results show the translocation of inhaled fly ash metals including Sr to extra-pulmonary organs. The study is not appropriate for derivation of a NOAEL.
Executive summary:

Wistar rats (170-175 g body weight) were exposed daily to fly ash in an inhalation chamber for 6 hours/d continuously for 15 days. The dust concentration in the chamber was maintained between 0.2 to 0.4 mg/L. The following metals of fly ash were analyzed: Na, K, Fe, Ca, Mg, Pb, Zn, Cu, Co, Ni, Cr, Mn and Sr. Their distribution in lung, liver, heart, kidney, small intestine and serum was studied. The strontium contents in all tissues were the lowest of all metals studied. The values tended to be higher at 1, 7 and 15 days. After 30 days, the fly ash strontium load from lung, liver, heart, kidney and small intestine was cleared. The results showed the translocation of inhaled fly ash metals including strontium to extra-pulmonary organs. However, this study is not considered to be of any relevance for risk assessment purposes.