RESUMO
Background: Region II in northern Chile (population 442 570) experienced a sudden major increase in arsenic water concentrations in 1958 in the main city of Antofagasta, followed by a major reduction in exposure when an arsenic removal plant was installed in 1970. It provides a unique opportunity to study latency effects of exposure to arsenic, and this is the first study with mortality data up to 40 years after exposure reduction. Methods: We previously identified high mortality rates in Region II up to the year 2000. Here we present rate ratios (RRs) for Region II compared with all the rest of Chile from 2001 to 2010, and with unexposed Region V (population 1 539 852) for all years from 1950 to 2010. All statistical tests were one-sided. Results: From 2001 to 2010, comparing Region II with the rest of Chile, lung and bladder mortality were still greatly elevated (RR = 3.38, 95% confidence interval [CI] = 3.19 to 3.58, P < .001 for lung cancer in men; RR = 2.41, 95% CI = 2.20 to 2.64, P < .001 for lung cancer in women; RR = 4.79, 95% CI = 4.20 to 5.46, P < .001 for bladder cancer in men; RR = 6.43, 95% CI = 5.49 to 7.54, P < .001 for bladder cancer in women). Kidney cancer mortality was also elevated (RR = 1.75, 95% CI = 1.49 to 2.05, P < .001 for men; RR = 2.09, 95% CI = 1.69 to 2.57, P < .001 for women). Earlier short latency acute myocardial infarction mortality increases had subsided. Conclusions: Lung, bladder, and kidney cancer mortality due to arsenic exposure have very long latencies, with increased risks manifesting 40 years after exposure reduction. Our findings suggest that arsenic in drinking water may involve one of the longest cancer latencies for a human carcinogen.
Assuntos
Intoxicação por Arsênico/mortalidade , Arsênio/efeitos adversos , Exposição Ambiental/efeitos adversos , Neoplasias Renais/mortalidade , Neoplasias Pulmonares/mortalidade , Neoplasias da Bexiga Urinária/mortalidade , Abastecimento de Água , Adulto , Idoso , Idoso de 80 Anos ou mais , Intoxicação por Arsênico/epidemiologia , Chile/epidemiologia , Feminino , Seguimentos , Humanos , Neoplasias Renais/induzido quimicamente , Neoplasias Renais/epidemiologia , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/epidemiologia , Masculino , Pessoa de Meia-Idade , Vigilância da População , Prognóstico , Taxa de Sobrevida , Neoplasias da Bexiga Urinária/induzido quimicamente , Neoplasias da Bexiga Urinária/epidemiologiaRESUMO
PURPOSE: In this study we assessed bladder cancer health care and mortality trends in recent decades in a well studied arsenic exposed area in Northern Chile. MATERIALS AND METHODS: Arsenic levels in the affected region were obtained for the last 60 years, and correlated with bladder cancer hospital discharge and mortality rates in recent decades. RESULTS: Bladder cancer hospital discharge rates were significantly higher in the affected region (peak RR 3.6, 95% CI 3.0-4.7). Mortality rates for bladder cancer showed a trend of increase during the period analyzed, reaching peak mortality rates of 28.4 per 100,000 for men and 18.7 per 100,000 for women in the last 10 years. Poisson regression models showed an increased mortality risk in the studied region compared to the rest of the country until the present for men (IRR 5.3, 95% CI 4.8-5.8) and women (IRR 7.8, 95% CI 7.0-8.7). Mean age at cancer specific death was significantly lower in the exposed region (69.6 years, 95% CI 68.4-70.7 vs 73.7 years, 95% CI 73.3-74.2, p <0.01). CONCLUSIONS: Exposure to arsenic is related to a significant need for bladder cancer health care and to high mortality rates even 20 years after having controlled arsenic levels in drinking water. Affected individuals should be aware of the significant impact of this ecological factor. Further research is required to identify strategies for the management of bladder cancer in arsenic exposed populations.
Assuntos
Intoxicação por Arsênico/complicações , Arsênio/análise , Neoplasias da Bexiga Urinária/induzido quimicamente , Abastecimento de Água/análise , Idoso , Intoxicação por Arsênico/mortalidade , Chile/epidemiologia , Feminino , Humanos , Incidência , Masculino , Distribuição de Poisson , Fatores de Tempo , Neoplasias da Bexiga Urinária/mortalidadeRESUMO
Arsenic in drinking water is known to be a cause of lung, bladder, and skin cancer, and some studies report cardiovascular disease effects. The authors investigated mortality from 1950 to 2000 in the arsenic-exposed region II of Chile (population: 477,000 in 2000) in comparison with the unexposed region V. Increased risks were found for acute myocardial infarction (AMI), with mortality rate ratios of 1.48 for men (95% confidence interval (CI): 1.37, 1.59; p < 0.001) and 1.26 for women (95% CI: 1.14, 1.40; p < 0.001) during the high-exposure period in region II from 1958 to 1970. The highest rate ratios were for young adult men aged 30-49 years who were born during the high-exposure period with probable exposure in utero and in early childhood (rate ratio = 3.23, 95% CI: 2.79, 3.75; p < 0.001). Compared with lung and bladder cancer, AMI mortality was the predominant cause of excess deaths during and immediately after the high-exposure period. Ten years after reduction of exposures, AMI mortality had decreased, and longer latency excess deaths from lung and bladder cancer predominated. With these three causes of death combined, increased mortality peaked in 1991-1995, with estimated excess deaths related to arsenic exposure constituting 10.9% of all deaths among men and 4.0% among women.