Biomonitoring of Exposure to Metals in a Population Residing in an Industrial Area in Brazil: A Feasibility Study.

BACKGROUND: Industries are sources of environmental pollutants. However, there are few human biomonitoring (HBM) studies in the vicinity of industrial areas. Thus, we evaluate the feasibility of conducting an HBM study to assess exposure to metals in an industrial area in Rio de Janeiro, Brazil. METHODOLOGY: A cross-sectional survey was conducted near a steel factory. Adults (exposed = 775; controls = 775) were randomly selected and sex-matched. Subjects were interviewed using a questionnaire and a 24 h dietary recall. Blood samples were collected to analyze metal concentrations, blood count, biochemical parameters, and thyroid hormones. The feasibility of the survey was assessed following guidelines. The descriptive analysis was performed for the first 250 participants (pilot study). RESULTS: Adjustments were made to the survey execution, including age-matching, fieldwork team, questionnaire, blood collection, and research awareness. The complete questionnaire was answered by ≥97% of participants; metals were measured in ≥98% and clinical parameters in ≥89%, except thyroid hormones (13-44%). The average age and family income were of 50 years and USD 575/month, respectively. The participants had equal distribution among sexes: 50% had a medium education level, and 59% were nonwhite. CONCLUSION: This preliminary HBM study demonstrates feasibility for the total population, with results indicating representativeness of the target population.

Perfil clínico-epidemiológico e sobrevida hospitalar dos casos de leucemia aguda em um hospital de referência em Rio Branco, Acre, 2007-2014 / Clinical epidemiological profile and survival of hospital cases of acute leukemia in a reference hospital in Rio Branco - Acre, 2007-2014

Resumo Introdução A Unidade de Assistência de Alta Complexidade em Oncologia (UNACON) permite o tratamento de leucemias agudas no Acre. Objetivo Determinar o perfil clínico-epidemiológico e a sobrevida hospitalar de leucemias agudas tratadas na UNACON/Acre entre 2007 e 2014. Método É um estudo longitudinal e retrospectivo de pacientes com leucemias agudas entre 15/06/2007 e 31/12/2014, cujos prontuários médicos forneceram dados para a análise descritiva das variáveis e posterior análise de sobrevida acumulada em 1 ano e 2 anos (método Kaplan-Meier) e comparação das curvas de sobrevida (teste de log-rank). Resultados A sobrevida para leucemias mieloides agudas (LMA) foi de 30% e 32% em 1 e 2 anos, respectivamente, com pior sobrevida para pacientes masculinos, brancos, ≥ 20 anos de idade, leucometria < 20.000 células/mm3, desidrogenase lática ≥ 600 U/dl e subtipo diferente do M3. Para leucemias linfoides agudas (LLA), a sobrevida foi de 59% e 45% em 1 e 2 anos, respectivamente, com pior sobrevida para sexo feminino, ≥ 20 anos de idade e leucometria elevada. Em pacientes abaixo de 20 anos de idade com LLA, a melhor sobrevida foi observada na faixa etária de 2 a 9 anos. Conclusão Trata-se do primeiro estudo epidemiológico de sobrevida realizado no Acre para leucemias agudas com resultados coerentes com a literatura. Contudo, novas pesquisas deverão ser realizadas.

Abstract Background The High Complexity Oncology Unit (Unidade de Assistência de Alta Complexidade em Oncologia - UNACON/Acre) allowed the treatment of acute leukemias in Acre. Objective To determine the clinical-epidemiological profile and hospital survival of acute leukemias treated at UNACON/Acre between 2007 and 2014. Method This is a longitudinal, retrospective study of patients with acute leukemias between 06/15/2007 and 12/31/2014 whose medical records provided data for descriptive analysis of the variables, and subsequent analysis of 1-year and 2-year cumulative survival (Kaplan Meier method) and comparison of survival curves (log-rank test). Results The survival for acute myeloid leukemia (AML) was 30 and 32% at 1 and 2 years, respectively, with a worse survival rate for males, white, age ≥20 years, leukometry <20,000 cells/mm3, lactic dehydrogenase ≥600 U/dl and subtype different from M3. For acute lymphoid leukemias (ALL), survival was 59 and 45% at 1 and 2 years, respectively. Female gender, age ≥20 years, and high leukometry had worse survival. For patients <20 years with ALL, better survival was observed in the age group of 2-9 years. Conclusion This is the first epidemiological study of survival in Acre for acute leukemias with results consistent with the literature. However, new studies should be performed.

Food Insecurity during Pregnancy in a Maternal-Infant Cohort in Brazilian Western Amazon.

The aim of this study was to determine the prevalence and analyze the factors associated with food insecurity during gestation in a maternal-infant cohort in Brazilian Western Amazon. A population-based cross-sectional study was conducted with parturients from a maternal-infant cohort in Rio Branco, located in the Western Brazilian Amazon. The dependent variable food insecurity (FI) was obtained through the Brazilian Scale of Food Insecurity, and associated factors were identified through multiple logistic regression. The prevalence of FI in pregnancy was of 34.8%. Regarding severity, the prevalence of mild food insecurity was 24.6%, moderate food insecurity was 4.8%, and severe food insecurity was 5.4%. The factors directly associated with FI were the presence of open sewage in the peridomestic environment; belonging to the lower economic classes; being an income transfer program beneficiary, while the factors inversely associated with FI were schooling equal to or greater than 8 years; having a partner; primigestation; and regular consumption of fruits and vegetables during pregnancy. These findings reinforce the need for the ratification of actions aimed at the domestic economy in the income transfer programs and the development of actions of food and nutritional education in the gestational period.

Sentinel Lymph Node Biopsy in Patients With Acral Melanoma: Analysis of 201 Cases From the Brazilian National Cancer Institute.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is the most powerful predictor of relapse-free survival (RFS) and overall survival (OS). No studies have evaluated survival of acral melanoma (AM) undergoing SLNB in Brazil. OBJECTIVE: The objective of this study was to investigate the factors associated with the survival of patients with AM undergoing SLNB. MATERIALS AND METHODS: Patients diagnosed with AM and submitted to SLNB were included in this study. We evaluated the epidemiologic, clinical, and histopathological data. Overall survival and RFS curves were estimated using the Kaplan-Meier method. Multivariable analyses were conducted using the Cox regression model. RESULTS: Among the 201 patients, 117 (58.2%) were female. The median age was 64 years old. Median tumor depth was 5.0 mm. Lesions were ulcerated in 134 (66.7%). Five-year OS and RFS rates were 44.6% and 38.6%, respectively. Median follow-up time was 39 months. The factors associated with OS were Breslow thickness, ulceration, and SLNB status, and for RFS, they were Breslow thickness and SLNB status. CONCLUSION: This is the largest series of AM submitted to SLNB. The 5-year OS and RFS rates were low (44.6% and 38.6%, respectively), and the main prognostic factors for OS were Breslow thickness, ulceration, and the status of SLNB.

Subungual melanoma: A retrospective cohort of 157 cases from Brazilian National Cancer Institute.

BACKGROUND: Subungual melanoma (SM) is rare. The lesions are thick at the time of diagnosis. Few studies have evaluated SM in Brazil. OBJECTIVE: The objective of this study was to investigate the factors associated with the survival of SM patients from the Brazilian National Cancer Institute. METHODS: One-hundred and fifty-seven patients diagnosed with SM were included in this study. We evaluated the epidemiologic, clinical, and histopathological data. Overall survival (OS) and relapse-free survival (RFS) curves were computed using the Kaplan-Meier method. Multivariable analyses were conducted using the Cox proportional hazard regression model. RESULTS: Among the 157 patients, 87 (55.4%) were female. The median age was 68 years old. Median tumor depth was 6.0 mm. Lesions were ulcerated in 94 (59.9%). OS and RFS rates for 5 years were 61.0% and 41.8%, respectively. Median follow-up time was 28 months. The factors associated with OS were Breslow thickness and ulceration, and for RFS, they were the anatomical site, Breslow thickness, and ulceration. CONCLUSION: This is the largest series of SM patients. The 5-year OS and RFS rates were low (61.0% and 48.2%, respectively), and the main prognostic factors for OS were Breslow thickness and ulceration.

Acral melanoma: a retrospective cohort from the Brazilian National Cancer Institute (INCA).

Acral melanoma (AM) is a rare subtype of melanoma arising on the palms, soles and subungual areas. In the Brazilian and Latin American populations, the sociodemographic and clinical-pathologic features of AM are unclear. AM tends to be more advanced at presentation because of delayed diagnoses, with poor survival. This study reports on a retrospective AM cohort from the Brazilian National Cancer Institute. We reviewed a database of 529 patients presenting with AM from 1997 to 2014 and analysed the sociodemographic and clinical-pathologic features of AM associated with overall survival and relapse-free survival. All patients were Brazilian, ranging in age from 19 to 101 years (mean 65.4; median 67.0). Two hundred and ninety-four (55.8%) patients were women. The Breslow primary lesion thicknesses ranged from 0.0 to 65.0 mm (mean 8.3 mm; median 5.0 mm). Of these patients, 43.3% had the acral lentiginous histologic subtype. Plantar was the most frequently involved site (68.5%), and ulcers and mitosis were present in 79.0 and 86.4% of these cases, respectively. Multivariate analysis results found that Breslow thickness of 1.03 (95% confidence interval: 1.01-1.05; P=0.01) and ulceration of 2.70 (95% confidence interval: 1.00-7.06; P=0.05) were poor prognostic indicators of overall survival. AM tumours were thick on diagnostic tests and were associated with poorer survival outcomes. Unfavourable prognosis likely derives from the delayed diagnosis compared with other melanoma subtypes.

Pesticide exposure and thyroid function in an agricultural population in Brazil.

Although numerous pesticides may interfere with thyroid function, however, epidemiological evidence supporting this relationship is limited, particularly regarding modern non-persistent pesticides. We sought to evaluate the association of agricultural work practices, use of contemporary-use pesticides, and OC pesticides residue levels in serum with circulating thyroid hormone levels in an agricultural population. A cross-sectional study was conducted with a random sample of 275 male and female farm residents in Farroupilha, South of Brazil. Information on sociodemographics, lifestyle and agricultural work was obtained through questionnaire. Blood samples were collected on all participants and analyzed for cholinesterase activity, serum residues of OC pesticides, and levels of free T4 (FT4), total T3 (TT3) and TSH. Non-persistent pesticides exposure assessment was based on questionnaire information on current use of pesticides, and frequency and duration of use, among others. Associations were explored using multivariate linear regression models. Total lifetime years of use of fungicides, herbicides and dithiocarbamates in men was associated with increased TSH accompanied by decrease in FT4, with evidence of a linear trend. In addition, there was an association between being sampled in the high pesticide-use season and increased TSH levels. Conversely, farm work and lifetime use of all pesticides were related with slight decrease in TSH and increased TT3 and FT4, respectively. In general, pesticide use was not associated with thyroid hormones in women. Subjects with detected serum concentrations of ß-hexachlorocyclohexane, endrin, dieldrin, heptachlor epoxide B, γ-chlordane, transnonachlor, heptachlor, p,p'-dichlorodiphenylethane and endosulfan II experienced slight changes in TT3; however, associations were weak and inconsistent. These findings suggest that both cumulative and recent occupational exposure to agricultural pesticides may affect the thyroid function causing hypothyroid-like effects, particularly in men.

Breast reconstruction and risk of lymphedema after mastectomy: A prospective cohort study with 10 years of follow-up.

OBJECTIVE: The aim of this study is to assess the incidence and risk factors for lymphedema in women submitted to mastectomy, with or without breast reconstruction. METHODS: A cohort study was performed on women submitted to mastectomy with axillary lymphadenectomy in a single center. The follow-up included clinical evaluation and arm column measurements before surgery, at 30 days, 6 months, 5 years, and 10 years after surgery. For women subjected to late reconstruction, the time of occurrence of lymphedema (before or after reconstruction) was observed. RESULTS: We followed up on 622 patients submitted to mastectomy and axillary lymphadenectomy for an average period of 57 months after surgery. In total, 94 women were submitted to breast reconstruction, 47 (8%) of them immediate and 47 (8%) late reconstructions. Incidence of lymphedema in the whole group was 33% (n = 204). Among the patients submitted to reconstruction, 28% of them developed lymphedema, on average, 93 months (CI 95%, 88-98) after surgical treatment. In women not subjected to reconstruction, 179 (34%) developed lymphedema, on average, after 106 months (CI 95%, 96-116) (p = 0.03). Breast reconstruction reduced lymphedema risk in 36% (HR = 0.64, CI 96%, 0.42-0.98, p = 0.04). After adjustment for pathological staging and radiotherapy, this was not statistically significant (HR = 0.79, CI 95%, 0.52-1.21, p = 0.28). CONCLUSION: Breast reconstruction does not increase the risk of lymphedema in long-term follow-up.

Exposição a pesticidas organoclorados e desenvolvimento cognitivo em crianças e adolescentes residentes em uma área contaminada no Brasil / Exposure to organochloride pesticides and the cognitive development of children and adolescents living in a contaminated area in Brazil

Avaliar o desempenho cognitivo de crianças e adolescentes residentes em uma área contaminada com pesticidas organoclorados (OC), e fatores associados à exposição. Métodos: realizou-se um estudo seccional com 102 indivíduos entre 6-16 anos residentes em Cidade dos Meninos, RJ, entre 2012-2013. Uma subamostra de 46 destas crianças dispunha das concentrações séricas de pesticidas OC e hormônios tireóideos, determinados entre 2003-2004. Local de residência materna e tempo de amamentação foram informados por todos os participantes. Desempenho cognitivo foi avaliado pela escala WISC-III. Utilizou-se regressão multivariada para explorar as associações. Resultados: pelo menos 40 por cento das crianças apresentaram inteligência inferior à média (QI<90) em seis domínios cognitivos. A função executiva demonstrou o menor escore. Local de residência materna e tempo de amamentação não associaram-se à cognição, exceto a função executiva. Níveis de alfahexaclorocicloexano (HCH) associaram-se a redução de 0,45, 0,33 e 0,46 pontos nas áreas de execução, resistência à distração (RD) e velocidade de processamento (VP), respectivamente; gama-HCH associou-se a redução de 1,74 pontos na RD e 1,84 pontos na VP; e p,p’-DDT (dicloro-difenil-tricloroetano) relacionou- se a menor pontuação (-0,81) na VP. Observou-se leve associação inversa entre os níveis de triiodotironina total e organização perceptual. Conclusões: resultados sugerem que a exposição crônica aos pesticidas OC poderia acarretar déficits cognitivos nestas crianças e adolescentes...

To assess the cognitive performance of children and adolescents living in an area contaminated with organochloride (OC) pesticides and factors associated with exposure. Methods: a cross-sectional study was conducted with 102 individuals aged between 6 and 16 years living in Cidade dos Meninos, in the Brazilian State of Rio de Janeiro, between 2012 and 2013. A subsample of 46 of these children had serum concentrations of OC pesticides and thyroid hormones determined between 2003 and 2004. Information on place of residence of the mother and duration of breastfeeding were provided for all participants. Cognitive performance was assessed using the WISC-III scale. Multivariate regression was employed to investigate associations. Results: at least 40 percent of the children presented with below average intelligence (IQ<90) in six cognitive categories. Executive function was the lowest score. Place of residence of the mother and duration of breastfeeding were not associated with cognition, except for the executive function. Levels of alphahexachlorocyclohexane (HCH) were associated with a reduction of 0.45, 0.33 and 0.46 points in the areas of execution, resistance to distraction (RD) and processing speed (PS), respectively; gamma-HCH was associated with a reduction of 1.74 points in RD and 1.84 points in PS; and p,p’-DDT (dichlorodiphenyl- trichloroethane) was associated with a lower score (-0.81) in PS. A slight inverse association was found between levels of total triiodothyronine and perceptual organization. Conclusions: the results suggest that chronic exposure to OC pesticides may have led to cognitive deficiencies in these children and adolescents...

Echocardiography in sickle cell anaemia patients under 20 years of age: a descriptive study in the Brazilian Western Amazon.

INTRODUCTION: Cardiac abnormalities in sickle cell anaemia are frequent and early, despite being more evident in adulthood. The study on cardiac abnormalities is essential in the current context, as, owing to improved health, children are increasingly able to reach adulthood and suffering the consequences of chronic cardiac injury. OBJECTIVE: The aim of this study was to determine the prevalence of echocardiographic changes in patients under 20, suffering from sickle cell disease in Rio Branco, Brazilian Western Amazon. METHODS: The descriptive epidemiological study compare two sets of children and adolescents, one including sickle cell anaemia patients (n=45), and other one (n=109) without sickle cell anaemia or heart disease. The echocardiographic measurements were indexed according to body surface using z-scores, and the prevalence of echocardiographic changes in both groups, with their respective 95% confidence intervals, ascertained and compared. RESULTS: Compared with the non-sickle cell anaemia series, the sickle cell anaemia group showed z-scores 13.1-fold higher for the diastolic diameter of the left ventricle, 5.2 times higher for the thickness of the posterior wall, 4.9 higher for the left atrium, 2.5 times higher for the right ventricle and 2.0 times higher for the septum thickness. Also the rate of left ventricular mass, systolic pressure of the right ventricle and the relative wall thickness were significantly higher in sickle cell anaemia set. CONCLUSIONS: Cardiac abnormalities were observed in 93.5% of patients. Early detection of cardiac abnormalities and quantifying them using the indexation of echocardiographic measurements according to body surface will allow proper identification and attendance of these children.

SULT1A1 genetic polymorphisms and the association between smoking and oral cancer in a case-control study in Brazil.

INTRODUCTION: Oral cancer is a public health problem worldwide, being tobacco and alcohol consumption their main risk factors. Sulfotransferase (SULT) 1A1 (encoded by SULT1A1) is involved in procarcinogens metabolism, such as polycyclic aromatic hydrocarbons (PAHs) present in tobacco smoke. OBJECTIVE: The aim of this study was to explore the magnitude of association between SULT1A1 gene Arg(213)His polymorphism and oral cancer, and to explore the interaction between such polymorphism and smoking. METHODS: A hospital-based case-control study was carried out in Rio de Janeiro, Brazil, during 1999-2002. Epidemiological data and biological samples were obtained from 202 oral cancer patients and 196 sex and age-frequency matched controls without cancer antecedents. RESULTS: No association was observed between Arg(213)His SULT1A1 polymorphism and oral cancer risk in overall analysis (OR = 1.06, 95% CI = 0.71-1.57). The magnitude of association between cigarette smoking and oral cancer was higher in individuals with a SULT1A1(*)1 isoform (wild type, genotype Arg/Arg) (OR = 10.19, 95% CI = 3.90-26.61) than in those with at least one SULT1A1(*)2 allele (genotypes Arg/His + His/His) (OR = 4.50, 95% CI =2.09-9.69). CONCLUSION: Our results suggest that Arg(213)His SULT1A1 polymorphism may modulate the association between smoking and oral cancer. However, this association needs to be replicated in other studies: due to modest number of cases and controls, the role of chance in the observed association cannot be ruled out.

Nomograms for predicting the risk of arm lymphedema after axillary dissection in breast cancer.

BACKGROUND: Lymphedema (LE) after axillary lymph node dissection (ALND) is a multifactorial, chronic, and disabling condition that currently affects an estimated 4 million people worldwide. Although several risk factors have been described, it is difficult to estimate the risk in individual patients. We therefore developed nomograms based on a large data set. METHODS: Clinicopathologic features were collected from a prospective cohort comprising 1,054 women with unilateral breast cancer undergoing ALND as part of their surgical treatment from August 2001 to November 2002. LE was defined as a volume difference of at least 200 ml between arms at 6 months or more after surgery. The cumulative incidence of LE was ascertained by the Kaplan-Meier method, and Cox proportional hazard models were used to predict the risk of developing LE on the basis of the available data at each time point: model 1, preoperatively; model 2, within 6 months from surgery; and model 3, at 6 months or later after surgery. RESULTS: The 5 year cumulative incidence of LE was 30.3%. Independent risk factors for LE were age, body mass index, ipsilateral arm chemotherapy infusions, level of ALND, location of radiotherapy field, development of postoperative seroma, infection, and early edema. When applied to the validation set, the concordance indices were 0.706, 0.729, and 0.736 for models 1, 2, and 3, respectively. CONCLUSIONS: The proposed nomograms can help physicians and patients predict the 5 year probability of LE after ALND for breast cancer. Free online versions of the nomograms are available at http://www.lymphedemarisk.com/ .

Prevalence of cryptosporidium spp. in domestic companion animals of elderly population in Teresópolis, Rio de Janeiro, Brazil / Prevalência de cryptosporidium spp. em animais domésticos de companhia da população em Teresópolis, Rio de Janeiro, Brasil

Este estudo visa a destacar a prevalência da criptosporidiose em animais de companhia doméstica. Método: Foram elegíveis para o estudo todos os idosos (acima de 60 anos de idade) de ambos os sexos que tenham cães e / ou gatos em casa, vivendo na cidade de Teresópolis e que foram a um posto de vacinação no município durante o período das campanhas nacionais de vacinação contra a gripe em 2007 e 2008. Resultados: Em 29,0% dos animais pesquisados detectou-se a presença de oocistos e em 28,7% foram observados 2 ou mais oocistos por campo. A prevalência de história de diarreia entre os 300 animais examinados foi de 27%, atingindo 29,5% em cães e 24,7% em gatos, não mostrando diferença estatisticamente significativa entre as espécies. Conclusão: Este fato indica lacunas a serem mais aprofundadas, uma vez que são poucos estudos que exploram a relação da criptosporidiose com os animais de companhia na população humana. Os resultados demonstram a importância de realização periódica de exames parasitológicos em cães com e sem diarreia para tratamento específico e adoção medidas de controle e profilaxia

Glutathione S-transferase polymorphisms and oral cancer: a case-control study in Rio de Janeiro, Brazil.

This study evaluates the influence of genetic polymorphisms at GSTM1, GSTT1 and GSTP1 gene loci on oral cancer susceptibility among Brazilians from Rio de Janeiro. DNA extracted from white blood cells of 231 oral cancer patients and 212 hospital controls was analyzed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods. GSTM1 polymorphism distribution was different between cases and controls (P=0.006), with an overrepresentation of GSTM1 A/B genotype in controls. GSTM1 A/B individuals were at decreased oral cancer risk (OR=0.08; 95% CI=0.05-0.62). No statistically significant association was observed for GSTT1 and GSTP1 polymorphisms. Differences in the GSTM1 and GSTT1 null genotype frequencies were observed between individuals of European origin and African origin, but these genotypes do not seem to influence the risk of oral cancer. Therefore, these results do not support the hypothesis of increased risk of GSTP1 G/G, GSTM1 or GSTT1 null genotypes for developing cancer in oral cavity, but the GSTM1 A/B genotype emerged as a protective factor.

CYP1A1 and CYP2E1 polymorphism frequencies in a large Brazilian population

The enzymes encoded by the polymorphic genes CYP1A1 and CYP2E1 play an important role in the activation and inactivation of xenobiotics. These enzymes have been associated with xenobiotic-induced diseases, such as cancer, therapeutic failure and adverse effects of drugs. The aim of the present study was to determine the allelic and genotypic frequencies of these polymorphisms in a large, ethnically mixed Brazilian population sample from Rio de Janeiro. Polymorphisms CYP1A1 and CYP2E1 were determined in 870 unrelated individuals by PCR-RFLP analysis in peripheral blood DNA. The observed allelic frequencies were 0.90 for CYP1A1*1A and 0.95 for CYP2E1*1A, in the total sample. The allelic frequency of CYP1A1*2C in "pardos" (0.13) and Brazilian whites (0.11) was higher than in Caucasians (0.05), which may be a result of the Amerindian genetic component, that presents the highest frequency of this allele observed up to now. The genotype distributions for both polymorphisms were in Hardy-Weinberg equilibrium and were statistically different between males and females, and among ethnic groups.

Influence of CYP1A1, CYP2E1, GSTM3 and NAT2 genetic polymorphisms in oral cancer susceptibility: results from a case-control study in Rio de Janeiro.

Xenobiotic metabolizing enzymes are involved in the detoxification of many carcinogens and may be important in modulating cancer susceptibility. CYP1A1, CYP2E1, GSTM3, and NAT2 polymorphisms were determined in peripheral blood DNA of 231 oral cancer patients and 212 hospital controls in Rio de Janeiro, Brazil, using the PCR-RFLP technique. NAT2 polymorphism distribution was different between cases and controls (P=0.035), with an overrepresentation of NAT2( *)11 mutant allele in controls. Risk analysis showed that NAT2 4/4 individuals (OR=1.95, 95% CI=1.05-3.60) and combined GSTM3 and NAT2 heterozygotes (OR=1.94, 95% CI=1.04-3.66) were at increased oral cancer risk. No statistically significant association was observed for CYP1A1 and CYP2E1 polymorphisms. Our results suggest that NAT2 polymorphism, alone or combined with GSTM3, may modulate susceptibility to oral cancer in Rio de Janeiro.

Cancer cluster among young Indian adults living near power transmission lines in Bom Jesus do Tocantis, Pará, Brazil

Avaliou a ocorrência de um agrupamento de casos de câncer em 1992, que se verificou em adultos jovens indígenas vivendo em aldeia na Amazônia, situada nas proximidades de duas linhas de transmissäo de 500 kV, as quais começaram a operar em 1982. Determinou-se os níveis sangüíneos atuais de DDT e pesticidas organofosforados, assim como a presença de metais em amostras de cabelo. A exposiçäo a campos eletromagnéticos de freqüência extremamente baixa foi determinada durante diversas atividades diárias desenvolvidas pelos indígenas. Considerando-se a incidência de câncer em diferentes cidades brasileiras, a probabilidade de ocorrência ao acaso deste agrupamento de casos foi considerada remota (p<0,03, distribuiçäo de Poisson). Níveis elevados de p.p'-DDT (mediana variando entre 26 e 58 ppb) foram observados nas amostras estudadas. A exposiçäo contínua aos campos eletromagnéticos de freqüência extremamente baixa, a qual atingiu 95 mG abaixo das linhas de transmissäo, foi observada em diversas oportunidades durante atividades diárias desenvolvidas pelos índigenas. Estudos observacionais futuros deveriam analisar a interaçäo da exposiçäo aos campos eletromagnéticos de freqüência extremamente baixa (50-60 Hz) subseqüente à exposiçäo a agentes de iniciaçäo tumoral no desenvolvimento de neoplasias.