Authors:S. Almeida, M. Freitas, C. Repolho, I. Dionísio, H. Dung, C. Pio, C. Alves, A. Caseiro, and A. Pacheco
Recent health studies evidence that epidemiological studies must be combined with accurate analyses of the physico-chemical
properties of the particles in order to determine the effects of atmospheric aerosols on human health. The project “Atmospheric
Aerosol Impacts on Human Health” focuses on the chemical characterization of PM2.5 aerosols with the aim to analyze the health
risks associated with exposure to aerosols and understand how their chemical composition contributes to the toxicity and human
health problems traditionally associated with fine particles. During one year, PM2.5 was collected daily, with a Partisol
sampler, in the centre of Lisbon. The aerosols were analyzed by Neutron Activation Analysis and Ion Chromatography in order
to determine their chemical composition. In parallel the clinical situation of students from the schools situated around the
sampler was followed. The incidence of asthma and rhinitis episodes was registered. Results showed that students were exposed
to PM2.5 concentrations that exceed the World Health Organization recommended levels. A marked sea influence in the aerosol
characteristics was identified by the use of air masses trajectories and by the concentrations of chloride, sodium and magnesium.
Authors:P. C. Favaro, P. Bode, and E. A. De Nadai Fernandes
Trace elements were determined in 27 brands of nail polish using INAA so as to estimate the impact of nail polish remainders when using (finger, toe) nail clippings as a bioindicator for epidemiological studies. Fe was found to be present up to almost 1.7% in one brand. No unambiguous correlation between trace elements and color was established, though transparent polish has the lowest trace element concentrations. An estimate of the maximum effect (no removal of the paint) indicates that over-estimates of some trace element levels in nail with more than 200.000% may occur. This study showed that if nail clippings will be used to study trace elements, very high demands have to be set to the efficiency and selectivity of the cleaning procedure.
Authors:M. Freitas, S. Almeida, A. Pacheco, I. Dionísio, C. Repolho, A. Caseiro, C. Pio, and C. Alves
In 2006, elementary schools of inner-city Lisbon, Portugal were given questionnaires to identify respiratory problems. In
1,175 children aged 5–10 years, 27.7% reported rhinitis, 2.5% reported hay fever and 25.9% reported asthma symptoms. April
and August were the months with higher incidence of rhinitis, with a considerable difference nonetheless (10.5% and 2.3%,
respectively.). The former trends are addressed here by using meteorological data, PM2.5, and its elemental speciation. Mann-Whitney U-tests were applied to the data sets. Significantly higher values were found for humidity, K+, NH4+, Sb and Zn in April, and for temperature, Cl−, Mg2+ and Na+ in August. Commuter and heavy-duty traffic may contribute to rhinitis episodes.
Authors:J. Morris, R. Ngwenyama, J. Guthrie, J. Brockman, V. Spate, and J. Robertson
Instrumental neutron activation analysis is routinely used at the MURR to quantify selenium in prospectively-collected biologic
markers including blood serum and toenails. These specimens are typically collected from well-defined cohort populations participating
in investigations assessing selenium intake and incidence of chronic disease endpoints. These epidemiological investigations,
whether observational (case-control) or clinical (intervention), typically generate thousands of samples. The purpose of this
paper is to assess, through evaluation of quality control results, if the achievable accuracy and precision in the measurement
of selenium using NAA is adequate to determine a relative risk of 1.2 at high confidence in epidemiological studies.
This study aims to investigate whether known carcinogenic chemical elements in atmospheric deposition might be associated
with child mortality due to leukemia in the Portuguese population. A Bayesian hierarchical model was used to explore the association
between lichen biomonitoring measurements of four elements—As, Hg, Ni, Pb—and childhood leukemia death counts taken at small
administrative units. This geographical epidemiological study found a non-significant positive association between the risk
of childhood leukemia and levels of arsenic, mercury and lead, and a non-significant negative association between the disease
and the level of nickel. Lead seems to show a weaker association with childhood leukemia than arsenic and mercury.
Lung cancer and smoking are associated. Epidemiological studies show that not only lung cancer but other chest diseases have
causative relationship with smoking. Cigarette tobacco and smoke contains many carcinogens. Inorganic and metallic constituents
of cigarette tobacco and smoke have not been studied as extensively as the organic compounds. Since some of the metals are
highly toxic and also carcinogenic, authors have attempted to measure the levels of some of the trace elements of Indian tobacco
by instrumental neutron activation analysis, and compared the results with the tobacco of America, Germany, Iran and New Zealand.
Authors:M. Menezes, E. Maia, C. Albinati, C. Sabino, and J. Batista
This paper describes the assessment of exposure levels to metals and possible workers' contamination in three galvanizing factories applying the same processes. Concerning the elements determined in air filters, 92.3% of them were also determined in hair and toenail samples: Ag, Al, As, Au, Cl, Cr, Cu, Fe, Mn, Na, Sb and Zn. These result point out that hair and toenail reflect the influence of the polluted environment on workers' health and can be useful as bioindicators in epidemiological studies. Instrumental neutron activation analysis was applied to all matrices which confirms its status as one of the most versatile analytical techniques.
The association of sub-optimal selenium status with increased riskfactors for some cancers has been reported in two recent epidemiological studies.In both studies the same threshold in selenium status was observed, belowwhich, cancer incidence increased. To assess the use of nails as a biologicmonitor to measure the long-term selenium status, an eight-year longitudinalstudy was undertaken with a group of 11 adult subjects, 5 women and 6 men.Selenium has been measured by instrumental neutron activation analysis. Differencesbetween fingernails and toenails will be discussed. In addition, the resultswill be discussed in the context of the long-term stability of the nail monitorto measure selenium status during those periods when selenium determinantsare static; and the changes that occur as a result of selenium supplementation.
Authors:M. Menezes, E. Pereira Maia, S. Filho, and C. Albinati
In order to assess the elemental concentration level in a galvanizing industry and alert for the need to assess the outcome of a long-term exposure, scalp hair and toenail samples were used as bioindicators and the industry environment was evaluated through airborne particulate matter. The elemental concentration results have pointed out a high exposure to pollutant at workplaces and a high elemental concentration in biomonitors suggesting endogenous contamination. The majority of the elements determined in airborne particulate matter were also determined in hair and toenail samples. The results evidence the efficiency of these matrixes as biomonitors and the importance to carry out the airborne particulate matter sampling in parallel to these biomonitors mainly in occupational epidemiological studies.
Authors:V. Spate, M. Mason, C. Reams, C. Baskett, J. Morris, and D. Mills
In this study we report on the comparison between the total selenium in serum (total Se) with that which is apparently bound to high molecular weight (>12,000 D) species, presumably proteins (bound Se). Nine hundred seventy seven (977) serum samples arising out of a population-based epidemiological study were prepared in duplicate for the determination of total Se by pipeting directly into irradiation vials; and separate duplicate aliquots were dialyzed against DI water for the determination of bound Se. All samples were analyzed by neutron activation analysis via77mSe (17.4 s). A small dialyzable Se component (6%) (free Se), defined as the difference between the total Se minus the bound Se, was identified.