title: Correlation between urinary nickel and testosterone plasma values in workers occupationally exposed to urban stressors.
abstract: BACKGROUND
  The purpose of this study is to assess whether occupational exposure to low doses of nickel (Ni) present in urban air can cause alterations in the concentration of plasma testosterone in workers of the Municipal Police of a large Italian city assigned to different types of outdoor tasks.
  
  
  METHODS
  359 male subjects were included in the study and divided on the basis of job, age, length of service and smoking habits. The dosage of the atmospheric Ni was performed by personal dosimetries on a sample of the workers included in the study. For each worker included in the study the dosage of whole blood Ni and of the plasma testosterone was carried out. The total sample was subjected to the independent-samples T-test and the Mann-Whitney U test for variables with 2 modes (smoking cigarette) and the ANOVA test and the Kruskal Wallis test for variables with more than 2 modes (age, length of service and job function). The correlation of Pearson with p at 2 wings between the variables was evaluated in the total sample and after subdivision on the basis of smoking and on the basis of the job. After taking into account the major confounding factors the multiple linear regression was performed on the total sample and after breakdown by tasks.
  
  
  RESULTS
  The correlation between the values of urinary Ni and the values of plasma testosterone on the total sample and for all classes of subdivision was found constantly negative. These results were confirmed by multiple linear regression, which indicated the Ni as the only significant variable that can contribute to the alterations of the testosterone.
  
  
  CONCLUSIONS
  Based on the results, the Authors suggest that occupational exposure to low doses of Ni present in the urban environment is able to influence some lines of the hypothalamic-pituitary-gonadal axis in exposed workers.
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Sancini
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: De Sio
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: P A
authors.initials: PA
authors.lastname: Gioffrè
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Casale
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Giubilati
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Pimpinella
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Scala
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Suppi
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Bonomi
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Samperi
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: M V
authors.initials: MV
authors.lastname: Rosati
authors.affiliation: Psychiatric and Psychological Science, Sapienza University of Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Tomei
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Tomei
authors.affiliation: Department of Anatomy, Histology, Medical-Legal and the Orthopedics, Unit of Occupational Medicine, Sapienza University of Rome, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Caciari
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000032:analysis / Q000633:toxicity*; D000704:Analysis of Variance; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism; D007558:Italy / Q000453:epidemiology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009532:Nickel / Q000032:analysis / Q000652:urine*; D016273:Occupational Exposure / Q000009:adverse effects*; D010913:Pituitary-Adrenal System / Q000378:metabolism; D016495:Police; D012907:Smoking / Q000453:epidemiology; D018709:Statistics, Nonparametric; D013739:Testosterone / Q000097:blood*; D013997:Time Factors
chemical_list: D000395:Air Pollutants, Occupational; D013739:Testosterone; D009532:Nickel