Guidelines biomonitoring of aluminium for thermal spray of aluminium

1. Biomonitoring of aluminum
Thermal Spray of Aluminium
TSA
October 2018
Bas de Barbanson
toxguide
Occupational Health Medicine

2. Contents
1 About toxguide
2 Toxicology
3 Definition and goal of biomonitoring
4 Exposure to aluminum
5 Health Effects of aluminum
6
Biomonitoring
7
Safe working procedures TSA
8
Questions?

3. 1 About toxguide
Former Dutch Occupational Health Officer ArboNed (1995-2011)
toxguide (2011-)
• Biological monitoring expert
• Advice safe work with chemicals
• Teacher Occupational Health

4. 2 Toxicology
Model (Green/Orange/Red)
• Exposure
• Individual hygiene/personal protection
• Health Effect
Paracelsus (1493-1541)
“Solo dosis facit venenum: “
• Water as a poison: “Marathon athlete dies after consuming 12 liter of water”
• Arsenicum as a tonicum: “Arsenikfresser in Switzerland”

5. 3 Definition and goal of biomonitoring
Biomonitoring
• Assesses the health risk through evaluation of the internal dose
• Main goal is to ensure that the current or past exposure of the workers is “safe”, i.e. , does not
entail an unacceptable health risk
• It is essentially a preventive medical activity
• The presence of a risk is appreciated by reference to permissible levels in biological media, i.e.,
health-based biological limit values

6. 4.1 Exposure to aluminum
(non-occupational)
Aluminum is a nonessential metal
Food constitues main source of exposure for the general population
Daily food intake 10mg-160mg
Uptake 1-5% in gastrointestinal tract
Non occupational human exposure of aluminum
• Use of aluminum-coated vessels (particularly when acidic foodstuffs are stored in lumnum
utensils)
• Treatment of water with aluminum compounds as flocculants in the purification process
• Aluminum containing drugs (antacids/phosphate binders)
• Aluminum contaminated parenteral fluids (parenteral nutrition, intravenous solutions,
contaminated dialysates)
• Aluminum based food additives
• Aluminum based antiperspirants
• Aluminium as adjuvant in vaccines
• …

7. 4.2 Exposure to aluminum
(occupational)
Sources of occupational exposure
• Smelting of aluminum
• Welding aluminum
• TSA aluminum: exposure generally >> exposure limits
• Production of aluminum flake powder
• Production of aluminum cement (Al2O3)
• …
Particle size of Al2O3
• If the particle size is below 10 µm than particles can penetrate deeply into the lungs and can
possibly damage the alveoli
This is crucial: all the kinds of severe lung damage (fibrose) are caused by the smaller particles

8. 4.3 Exposure to aluminum TSA:
> Limit values (Germany, 2012)
http://publikationen.dguv.de/dguv/pdf/10002/bgi593e.pdf

9. 4.3 Exposure to aluminum TSA:
Generation fine particles +++
(French, 2012)
Study TSA (Bemer e.a. France, 2010)
• Generation of extra fine particles during TSA needs careful consideration protection measures

10. 4.2 Guidelines aluminum in air
Different Occupational Exposure Limits for Aluminum in some countries
Respirable Metal Dust ( dust penetrating in the alveoli of the lung)
NL (GR, 2010):
0,05 mg/m3 (Aluminum chloral hydrate=Al in deodorant)
US (ACGIH,2013):
1 mg/m3
Belgium (Belgisch Staatsblad, 2009):
1 mg/m3
Germany (DFG, 2013):
1,5 mg/m3
Sweden (SWEA,2011):
2 mg/m3
Europe (REACH,2007):
3,72 mg/m3
US (NIOSH, 2012):
5 mg/m3

11. 5.1 Health Effects of aluminum (Short-
term)
Short-term exposure: possible health effects
•
Irritating eyes/nose (particles deposited in the eye can scratch the eyes and may cause
necrosis of the cornea)
•
Irritating respiratory tract: causes metal fume fever (cough, chest pain, flu-like fever;
symptoms may be delayed for 4-12 hours following exposure)
•
Pneumonia

12. 5.2 Health Effects of aluminum (Long-
term)
Long-term exposure: possible health effects
Long-term occupational exposure to aluminum dusts can lead to accumulation in the body. The
urine is the main route of excretion, explaining the high risk of aluminum accumulation in humans
with impaired renal function.
•
Pulmonary fibrosis
scarring, serious lung damage
•
Pulmonary granulomatosis
allergic reaction with chronic pneumonia
•
Neurological effects
slight disturbance – severe brain damage: dementia/parkinson/ALS/
seizures /speech disorders /eye retina damage
•
Blood anemia
similar to lead poisoning
•
Bone disease
osteomalacia
•
Reprotoxic effects
animal testing: male reproductive toxicity
•
Carcinogenic effects
not classifiable as a human carcinogen
• …

13. 5.3 Toxicity of aluminum (serum levels)
Long term inhalation of aluminum dust can lead to accumulation of aluminum in the body, which
takes place over years. Uptake by ingestion is normally very low (+/- 1-5%).
Aluminum is a very potent neurotoxicant.
Serum levels 30 µg/L
• in dialysed patients have been associated with osteomalacia (bone disease)
Serum level 50 µg/L
• Subtle neurocognitive (= memory ) and psychomotor effects and electroencephalograph (EEG)
abnormalities have been reported at plasma levels as low as 50 µg/L.
Serum level > 80µg/L
• generally associated with post-dialysis encephalopathy. (= brain damage)
NB Workers who are exposed to lead tolerate much higher levels without effect: blood lead levels
of 100 µg/L has no deleterious effect on the body.

14. 6.1 Biological monitoring of aluminum
Biological monitoring of aluminium compounds
• Primary objective of aluminum biomonitoring is to help prevent the formation of aluminum
burden in the lungs and thereby to prevent harmful accumulation of aluminum in other target
organs
NB The halftime of aluminum in the body is dependent on the composition and seems to increase
with the duration of exposure (10 hours- 10 years)
Measurement of aluminum in urine is preferable to serum to assess occupational exposure
• Aluminum end of shift and end of workweek mainly reflects recent exposure
• Aluminum preshift first day of the week mainly reflects body burden.
Aluminum in urine
•
Reference value: < 10 µg aluminum/gram creatinine in
•
Guideline value: < 60 µg aluminum/gram creatinine (Germany BAT Value, MAK Werte 1,5 mg/
m3)

15. 6.2 Interpretation of results
biomonitoring
On a group basis aluminum concentration is related to airborne aluminum concentration
Specimen collection
• End of shift, end of workweek:
mainly reflects recent exposure
• Preshift first day of workweek:
mainly reflects body burden
Results Aluminum in urine
< 10
µg/gram creatinine =
“normal”
10- 60
µg/gram creatinine=
”light-intermediate exposure”
> 60
µg/gram creatinine =
“exceeding limit”
Toxic values aluminum in urine
> 100
µg/gram creatinine=
may damage the nervous system (welders of aluminum)!

16. 6.2 Interpretation of results: relation
between Al in air and Al in urine
(example, DFG Germany)

17. 7 TSA: Safe working procedure
Conclusion
INRS (France, 2012)
• TSA generates high ultrafine particle (< 100 nanometer) emissions of aluminum and therefore
requires careful consideration and possible rethinking of currently implemented protection
measures!
toxguide advice (Netherlands, 2017)
• Protect the workers conform the lead procedure!
• Check the preventive measures by performing biological monitoring of aluminum preshift and
postshift

18. 8 Any questions?
Bas de Barbanson
E: info@toxguide.nl
M: 06 53 23 55 72