Quaranta et al. BMC Public Health 2011, 11:774 http://www.biomedcentral.com/1471-2458/11/774 the main complications have been oedemas, infections, hemorrhages and, in some cases, hospital treatments. Almost 10% of the subjects with a piercing on the ton- gue were performed by “non-specialists."; as a matter of fact in that paper, the tongue has turned out to be the part of the body where the majority of injuries related to piercing occurred [2]. Tattoos are also responsible for infectious complications: bacterial endocarditis [20], aty- pical mycobacterial infections [21], erythematic nodules [22]. In Italy, in April 1998, an appropriate intervention was promoted by the Ministry of Health to fight this phenomenon and the risks related through the publica- tion of “Guidelines for the procedures of tattoos and piercing in health and safety conditions”, whose last update was in 2004 [23]. The aim of the present study is to ascertain young Ita- lian adults’ knowledge, attitudes and practices with regard to the risk related to “tattooing-piercing” through an investigation among university freshmen in Bari, Southern Italy. Methods Study procedures The study was carried out in the first half of the Aca- demic Year 2009-2010. Through a non-probabilistic quota sampling, 1.656 freshmen were selected among 17 Degree Courses of the University of Bari, Italy. The courses were grouped in three main fields: sanitary (Faculty of Medicine and Surgery), scientific (Faculty of Architecture, Engineering, Bio-Technological Science, Mathematics-Physics and Natural Sciences) and humanistic (Faculty of Literature and Science of Education). The selection of subjects to be enrolled in the study was performed carrying out the sampling until the fulfilling of each quota (at least 33%) for the three recruitment categories. The sample was asked to complete an anonymous questionnaire. All par- ticipants took part on a voluntary basis and were not remunerated for participation. The questionnaire The form reporting the questions was divided into three sections: 1. Questions about age, sex, place of residence and parents’ occupation. According to the “US Census Bureau” [24] occupations were classified in skill levels (skilled, semi-skilled, low/unskilled, unemployed). 2. Closed-ended questions about the participant’s knowledge of the actual health risks linked to the prac- tices of tattooing and piercing. Some questions allowed “yes"/"no"/"don’t know” answers (e.g. “Is it risky under- going piercing/tattooing?"; “Are the places and instru- ments used for body art always safe in terms of health and hygiene?”); other questions included the possibility Page 2 of 8 of multiple choices (e.g. “If tattoos and piercing can transmit infectious diseases, which of those listed below?"; “Which of the non-infectious diseases listed below can follow a piercing and tattoo?”). 3. Limited to people who underwent body art and dis- tinct in two subsections: one for piercing and one for tattooing. Closed-ended questions with “yes"/"no"/"don’t know” regarding advice required before practices, infor- mation given to the parents, giving informed written consent, acquisition of information regarding health risks. Closed-ended questions with multiple choices regarding: decision-making (including input from others), reasons for having the body art, place where the procedure was carried out; location of the tattoo/pier- cing, any complications reported. Open questions regarding the age at which the tattoo/piercing was car- ried out for the first time, and on how many piercings/ tattoos young adults have. Data analysis The data collected have been inserted in a database. Sta- tistical analysis was executed by the Statistical Pro- gramme R version 2.8.0. Student’s t-test was used to compare unpaired data; the c2 statistical test was used to evaluate the association between independent vari- ables. The relative confidence intervals at 95% were cal- culated and a value of p < 0.05 was considered significant for all the tests. According to Schorzman et al [15], since in western society it is customary for women to wear earrings on both earlobes it was specified on the survey that, for women, piercing was to be considered “a metal object inserted in the skin in any part of the body, with the exception of the earlobes"; for men, instead, the orna- ment of the earlobes could be considered a piercing. The research does not report any experiment on human or biological human samples; it is an observational sur- vey conducted by an anonymous questionnaire among freshmen approved by the Apulia Regional Epidemiolo- gical Center (Scientific Body of the Regional Health Authority). Results Of the 1.656 enrolled freshmen, 1.598 returned a cor- rectly filled out questionnaire (96.5%) and were consid- ered for the analysis: 33.8% came from humanistic, 33.1% from healthcare and 33.1% from the scientific faculties. Of the 1.598, 508 (31.8%) were male and 1.090 (68.2%) were female. The average age of participants was 20.15 years (range 17-58; SD = ±3.4); considering that in Italy the usual university freshmen age group ranges between 17-19 years, 62.7% (1.002/1.598) fell into this range. Of the students included in the analysis, 332 (20.8%)