Naphthenic acids, nickel salts

Epidemiological data

Administrative data

Endpoint:

epidemiological data

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Sept 2007 - April 2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Meets generally accepted scientific standards, well documented and acceptable for assessment.

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:

Nickel and blood counts in workers exposed to urban stressors.

Author:

Rosati MV, Casale T, Ciarrocca M, Weiderpass E, Capozzella A, Schifano MP, Tomei F, Nieto HA, Marrocco M, Tomei G, Caciari T, Sancini A.

Year:

2014

Bibliographic source:

Toxicol Ind Health. 2014 Jul 7.

Materials and methods

Study type:

cross sectional study

Endpoint addressed:

other: Blood CBC cell counts

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Estimate exposure of individuals to Ni and examine the correlation between this exposure and the values of blood counts in outdoor workers.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

environmental nickel

IUPAC Name:

environmental nickel

Details on test material:

Environmental nickel

Method

Type of population:

occupational

Ethical approval:

not specified

Details on study design:

This study focused on a sample of 101 outdoor workers (55 male and 46 female; 65 nonsmokers and 36 smokers), all employed in the municipal police in a large Italian city. The personal levels of exposure to Ni were assessed through (a) environmental monitoring of Ni present in the urban air obtained from individual samples and (b) biological monitoring of urinary and blood Ni. The blood count parameters were obtained from the hemochromocytometric tests. Pearson correlation coefficients (r) were calculated to assess the association between the blood and urinary Ni and the complete blood count. Multiple linear regression models were used to examine the associations between the complete blood count and the independent variables (age, gender, years of work for current tasks, cigarette smoking habit (current and never smoker), values of airborne Ni, and blood and urinary Ni).

Exposure assessment:

measured

Details on exposure:

The individual exposure to Ni compounds in air was evaluated through the use of portable dosimeters in 8 working areas considered representative of urban air quality; 101 personal samples were collected in the studied population. The individual air samples were collected using Dorr-Oliver cyclone with a 5-μm diameter cut point for particles. Each cyclone was attached to a pump for personal air sampling; the pump was calibrated to a flow rate of 1. 7 L of air for 1 min, following the National Institute of Occupational Health regulations. Each cyclone was fitted with a cassette holding a membrane filter of 37 mm made of polyvinyl chloride. The cyclone and the cassettes were attached to the worker's collar in the breathing zone. After sampling, the cyclone was carefully dismantled. The filter membranes containing the particulates were analyzed for Ni using the 7521 method. The "digested" particulate samples were analyzed by atomic absorption spectrometry in a graphite furnace (Perkin Elmer, model HGA- 2100, Waltham, Massachusetts, USA). For each sample of air, the level of the individual time-weight average (TWA) exposure to Ni for 7 h was calculated. All subjects were asked not to smoke during the sampling procedure. Also, on the same day of individual sampling, blood and urine samplings were collected from each worker.

Statistical methods:

The normal distribution of variables was tested using the Kolmogorov-Smirnov test. The results were expressed as the mean, the standard deviation, and the range (min-max). The results that were lower than the LoD, both for the personal samples and for the biological monitoring, were expressed in values corresponding to the LoD divided by the square root of 2. Pearson's correlation coefficients (r) were calculated on the log-transformed data to assess the association among the blood, urinary Ni, and personal air samples and among the blood, urinary Ni, and CBC. The correlation analysis between the values of blood and urinary Ni and the values of CBC was performed on the total sample and on the sample divided for gender (male and female) and smoking habit (current smoker and never smoker). Multiple linear regression models were used to examine the associations between CBC and the independent variables (age, gender, years of work in the current task, cigarette smoking habit (current smoker and never smoker), and concentrations of the airborne Ni and blood and urinary Ni) on the total group (n = 101 subjects). The value of p < 0.05 was considered significant. The statistical analysis was performed using the statistical software Statistical Package for Social Sciences version 20 for Windows.

Results and discussion

Results:

The total sample of 101 subjects was composed of 55 males and 46 females; 65 subjects had never smoked and 36 were current smokers. The mean (SD) values of the individual exposure to Ni in the air were 170.04 ng.m3 (356.11) 7 hr TWA. None of the workers smoked during the sampling. No samples exceeded the limit level of 1.5 mg/m3 suggested by the American Conference of Governmental Industrial Hygienist (ACGIH) for subjects occupationally exposed to Ni. All values of the urinary creatinine were within the reference range (0.3-3.0 g/L) recommended by the World Health Organization. The blood and urinary Ni concentrations were lower than LoD in 7 (6.933) and in 6 (5.943) workers, respectively. The levels of both the blood and the urinary Ni were significantly correlated with the levels of Ni in air measured by individual samples in the total sample. As far as CBC was concerned, several significant correlations were identified between the different CBC variables and the blood/urinary Ni levels in the total sample and in different subgroups divided by gender and cigarette smoking habits. The multiple linear regression analysis performed on the total group of 101 subjects showed that (a) the log concentrations of the urinary Ni were dependent on the log concentrations of airborne Ni (R2 = 0.725; p = 0.000) and (b) the log concentrations of the blood Ni were dependent on the log concentrations of airborne Ni (R2 = 0.624; p = 0.000). The multiple linear regression analysis performed on the total group of 101 subjects confirmed the association among the levels of RBCs and urinary Ni (R2 = 0.520;p = 0.025) and Hct and the urinary Ni (R2 = 0.530; p = 0.030). The multiple linear regression analysis did not show any other significant association.

Confounding factors:

Exposure to other metals, benzene, toluene, and other heavy metals or other pollutants present in the urban air.

Strengths and weaknesses:

Strengths of this study include personal monitoring on the day of sample collection. Weaknesses include its cross-sectional design and one-time sampling that does not allow for a determination of causation.

Applicant's summary and conclusion

Executive summary:

Study rated by an independent reviewer