Cadmium hydroxide

Epidemiological data

Administrative data

Endpoint:

epidemiological data

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 1947 to 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

All selected studies were evaluated with a check-list relating to population, exposure, endpoints, biases and confounders. Used check-list are established by Professor Philippe Hotz from the Institut für Sozial- und Präventivmedizin der Universität Zürich (EU RA 2008).

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

Lung cancer mortality in UK nickel-cadmium battery workers, 1947-2000

Author:

Sorahan T and Esmen NA

Year:

2004

Bibliographic source:

Occup. Environ. Med. 61(2):108-116.

Materials and methods

Study type:

cohort study (prospective)

Endpoint addressed:

carcinogenicity

Principles of method if other than guideline:

Epidemiological study was conducted to determine the association between the risk of dying from lung cancer and occupational cadmium exposure.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Cadmium hydroxide

EC Number:

244-168-5

EC Name:

Cadmium hydroxide

Cas Number:

21041-95-2

Molecular formula:

CdH2O2

IUPAC Name:

cadmium hydroxide

Details on test material:

- Name of test material (as cited in study report): Cd(OH)2 dust

Method

Type of population:

occupational

Ethical approval:

not specified

Details on study design:

HYPOTHESIS TESTED (if cohort or case control study): Association between the risk of dying from lung cancer and occupational cadmium exposure

STUDY PERIOD: 1947-2000

STUDY POPULATION
E: 926 (M)
S: “workers first employed in the period 1947-1975 and having a minimum of 12 months of employment at the factory”
Lost cases: 26 emigrated, 4 untraced

Exposure assessment:

estimated

Details on exposure:

Exposure levels and categories:
air Cd levels: : surveys 1957-1992 (area measurements), 1964-1992 (personal sampling)
Cumulative exposure categories
< 400 µg/m³/year
400-1599 µg/m³/year
1600-4799 µg/m³/year
≥ 4800 µg/m³/year

Statistical methods:

external - internal standards

Results and discussion

Results:

-overall:
prostate cancer (o/e) : 9/7.5
SMR (95% CI) prostate: 116 (53-221)

Lung cancer (o/e) : 45/40.7
SMR (95% CI) lung: 111(81-148)
→ Non significantly increases in lung/ prostate cancer deaths

Confounding factors:

Considered confounders:
- Smoking: N.I.
- Other simultaneous exposures: N.I.; exposure to Cd(OH)2 dust, nickel hydroxide, cobalt, graphite, iron oxide, potassium hydroxide

Strengths and weaknesses:

Weakness:
limitations as reported by the authors:
- data not available for the earlier years of exposure,
- no direct measurements available for workers in the "non-exposed" departments,
- smoking data not available
- irregular trend patterns shown by the raw exposure data believed to be due to limitations of happenstance sampling.

Any other information on results incl. tables

There was a significantly increased mortality for cancers of the pharynx, non-malignant diseases of the respiratory system and non-malignant diseases of the genitourinary system. Non-significantly increased SMRs were shown for lung cancer and cancer of the prostate.

Table 1: Mortality of male workers from a nickel-cadmium battery factory, 1947-2000 (Sorahan and Esmen, 2004) Summary of the main results

Cause of death	Obs.	Exp.	SMR	95% CI
All causes	422	384.0	110	100-121
All neoplasms	123	109.2	113	94-134
Cancers of the pharynx	4	0.7	559*	152-1432
Lung and bronchus cancer	45	40.7	111	81-148
Prostate cancer	9	7.5	116	53-221
Diseases of respiratory system	61	43	142*	109-182
Diseases of genito-urinary system	10	4.1	243*	116-446

*: p<0.05

Estimated cumulative cadmium exposures were not related to risks of lung cancer or risks of chronic obstructive pulmonary diseases, even when exposure histories were lagged first by 10, then by 20 y.

Table 2: Rate ratios (relative risks) for lung cancer and for chronic obstructive pulmonary disease in relation to cumulative exposure to cadmium (Sorahan and Esmen, 2004)

Cumulative exposure to cadmium (µg/m^3/y)	Exposure histories
	Unlagged		Lagged by 10 years		Lagged by 20 years
	n	RR	n	RR	n	RR
Lung cancer
<400	11	1.0	18	1.0	27	1.0
400-1199	19	2.04	17	2.05*	9	1.76
1200-4799	9	1.02	5	0.59	7	1.21
> or = 4800	8	1.02	7	0.97	4	0.77
P value for trend		p>0.50		p>0.50		p>0.50
Chronic obstructive pulmonary disease
<400	18	1.0	25	1.0	34	1.0
400-1199	15	0.96	14	1.14	12	1.64
1200-4799	10	0.65	10	0.77	5	0.62
> or =  4800	16	1.20	10	0.93	8	1.21
P value for trend		p>0.50		p>0.50		p>0.50
All causes
<400	127	1.0	174	1.0	242	1.0
400-1199	103	0.97	88	0.98	65	1.12
1200-4799	99	0.93	87	0.93	66	1.05
> or = 4800	93	1.05	73	0.97	49	0.95
P value for trend		p>0.50		p>0.50		p>0.50

*: p<0.05

Applicant's summary and conclusion

Conclusions:

The study findings do not support the hypotheses that cadmium compounds are human lung carcinogens.

Executive summary:

This study by Sorahan and Esmen (2004), an update of the previous mortality Sorahan, 1997, investigate the mortality from lung cancer for the period 1947-2000 in workers first employed in the period of 1947-1975 and having a minimum of 12 months employment at the factory in relation to cumulative exposure to cadmium hydroxide. Hence, this report incorporates quantitative cadmium exposure into updated follow up data from thestudy of nickel-battery workers (Sorahan, 1987).

 

Exposure reconstruction was based on estimation of cumulative cadmium exposure (detailed job histories) by consideration of all available measurements (area measurement: 1957-1992, personal sampling: 1964-1992). Based on serial mortality rates for the general population ofand, significantly increased mortality was shown for cancers of the pharynx (Observed: 4, Expected: 0.7, SMR: 559, 95% CI: 152-1432). Non-significantly increased SMRs were shown for lung cancer (Observed: 45, Expected: 40.7, SMR: 111, 95% CI: 81-148) and cancer of the prostate (Observed: 9, Expected: 7.5, SMR: 116, 95% CI: 53-221). Estimated cumulative cadmium exposure was not related to risks of lung cancer, even when exposure histories were lagged first by 10, then by 20 y.

 

As concluded by the authors, the study findings do not support the hypotheses that cadmium compounds are human lung carcinogens.