Biol Trace Elem Res (2013) 156:29–35 DOI 10.1007/s12011-013-9849-7
Mercury in Scalp Hair Near the Mid-Atlantic Ridge (MAR) in Relation to High Fish Consumption H. C. Vieira & F. Morgado & A. M. V. M. Soares & S. N. Abreu
Received: 13 June 2013 / Accepted: 16 October 2013 / Published online: 1 November 2013 # Springer Science+Business Media New York 2013
Abstract The aim of this study was to evaluate the potential risk of mercury contamination near the Mid-Atlantic Ridge relating total mercury (THg) concentrations in the human scalp hair (n =110) and high fish consumption levels. THg was quantified in human scalp hair, and volunteers were questioned about age, gender, and smoking habits being subsequently grouped in categories based on the individual average intake of fish meals per week. THg concentrations ([THg]) in hair samples ranged from 0.05 to 2.24 μg g−1, and significant differences were found according to age (p 65 years old). The hair samples were obtained by a single cutting from the occipital region using clean stainless steel scissors. The samples were then kept in clean microtubes of 2 ml and identified appropriately. In the laboratory, the hair samples were cut to lengths of about 2 cm segments and washed according to the standard procedure recommended by the International Atomic Energy Agency: wash in acetone, three times in water, and once more in acetone [28]. The samples were after dried overnight in an oven at 40 °C. During scalp hair sampling, each individual was asked to complete a questionnaire detailing age, gender, body weight,
Mercury Quantification Mercury determination was performed by atomic absorption spectrometry after thermal decomposition of the sample using the Advanced Mercury Analyser (AMA-254, LECO). This technique of quantification is based in a pyrolysis process of the sample using a combustion tube heated at 750 °C under an oxygen atmosphere. Volatilized mercury Hg(0) is trapped in a gold amalgamator and subsequently detected and quantified by atomic absorption spectrometry [29]. Analytical quality of the procedure was controlled using reference material TORT-2 (Lobster Hepatopancreas Reference Material for Trace Metals , National Research Council of Canada) containing 0.27±0.06 μg g−1 of THg and DORM-3 (Fish Protein Certified Reference Material for Trace Metals , National Research Council of Canada) containing 0.382±0.06. Obtained data and reference values are not statistically different with a recovery percentage of 90 and 88 %, respectively.
Statistical Analysis Outliers were removed following an observation of THg boxplot, and data normality was tested through Kolmogorov-Smirnov test. Data did not follow a normal distribution, and the normality was established after logtransformation; therefore, the parametric statistical one-way ANOVA was used to compare mercury concentration with various socioeconomic variables, and Tukey test was used to determine significant differences in fish consumption groups and age groups. Spearman correlation was used to test the correlation between THg levels and fish consumption. Statistical analysis was assessed using SPSS (version 15.0). Statistical significance was defined as p
Mercury in Scalp Hair Near the Mid-Atlantic Ridge (MAR) in Relation to High Fish Consumption H. C. Vieira & F. Morgado & A. M. V. M. Soares & S. N. Abreu
Received: 13 June 2013 / Accepted: 16 October 2013 / Published online: 1 November 2013 # Springer Science+Business Media New York 2013
Abstract The aim of this study was to evaluate the potential risk of mercury contamination near the Mid-Atlantic Ridge relating total mercury (THg) concentrations in the human scalp hair (n =110) and high fish consumption levels. THg was quantified in human scalp hair, and volunteers were questioned about age, gender, and smoking habits being subsequently grouped in categories based on the individual average intake of fish meals per week. THg concentrations ([THg]) in hair samples ranged from 0.05 to 2.24 μg g−1, and significant differences were found according to age (p 65 years old). The hair samples were obtained by a single cutting from the occipital region using clean stainless steel scissors. The samples were then kept in clean microtubes of 2 ml and identified appropriately. In the laboratory, the hair samples were cut to lengths of about 2 cm segments and washed according to the standard procedure recommended by the International Atomic Energy Agency: wash in acetone, three times in water, and once more in acetone [28]. The samples were after dried overnight in an oven at 40 °C. During scalp hair sampling, each individual was asked to complete a questionnaire detailing age, gender, body weight,
Mercury Quantification Mercury determination was performed by atomic absorption spectrometry after thermal decomposition of the sample using the Advanced Mercury Analyser (AMA-254, LECO). This technique of quantification is based in a pyrolysis process of the sample using a combustion tube heated at 750 °C under an oxygen atmosphere. Volatilized mercury Hg(0) is trapped in a gold amalgamator and subsequently detected and quantified by atomic absorption spectrometry [29]. Analytical quality of the procedure was controlled using reference material TORT-2 (Lobster Hepatopancreas Reference Material for Trace Metals , National Research Council of Canada) containing 0.27±0.06 μg g−1 of THg and DORM-3 (Fish Protein Certified Reference Material for Trace Metals , National Research Council of Canada) containing 0.382±0.06. Obtained data and reference values are not statistically different with a recovery percentage of 90 and 88 %, respectively.
Statistical Analysis Outliers were removed following an observation of THg boxplot, and data normality was tested through Kolmogorov-Smirnov test. Data did not follow a normal distribution, and the normality was established after logtransformation; therefore, the parametric statistical one-way ANOVA was used to compare mercury concentration with various socioeconomic variables, and Tukey test was used to determine significant differences in fish consumption groups and age groups. Spearman correlation was used to test the correlation between THg levels and fish consumption. Statistical analysis was assessed using SPSS (version 15.0). Statistical significance was defined as p
