Thomas Sinks

Assessment of a severe-weather warning system and disaster preparedness, Calhoun County, Alabama, 1994

Tornado preparedness warning system effectiveness, and shelter-seeking behavior were examined in two Alabama areas after tornado warnings. In the area without sirens, only 28.9% of 194 respondents heard a tornado warning of these, 73.2% first received the warning from radios or television. In the area with sirens, 88.1% of 193 respondents heard a warning, and 61.8% first received the warning from a siren. Knowledge of warnings, access to shelter, and education were key predictors for seeking shelter. Our findings indicate that installing sirens, providing access to shelter, and teaching appropriate responses to warnings are important elements of an effective disaster prevention system.

Understanding Cancer Clusters

Each year, state and local health departments respond to more than 1,000 inquiries about suspected cancer clusters. Three quarters of these reports involve situations that are clearly not clusters and can be resolved by telephone. For the remainder, follow‐up is needed, first to confirm the number of persons affected, their age, type of cancer, dates of diagnosis, and other factors, and then to compare cancer incidence in the affected population with background rates in state tumor registries. In approximately 5% to 15% of the reported situations, formal statistical testing confirms that the number of observed cases exceeds the number expected in a specific area, given the age, sex, and size of the affected population. Even in these instances, however, chance remains a plausible explanation for many clusters, and further epidemiologic investigation almost never identifies the underlying cause of disease with confidence. The few exceptions have involved clusters of extremely rare cancers occurring in well‐defined occupational or medical settings, generally involving intense and sustained exposure to an unusual chemical, occupation, infection, or drug. This article discusses the resources and scientific tools currently available to investigate cancer clusters. It also provides a framework for understanding cancer clusters and a realistic appraisal of what cluster investigations can and cannot provide in the context of community expectations.

Things to Know and Do About Cancer Clusters

Perceived cancer clusters present difficulties and opportunities for clinicians and public health officials alike. Public health officials receive reports of perceived cancer clusters, evaluate the validity of these reports, and/or launch investigations to identify potential causes. Clinicians interact directly with the affected patients, families, or community representatives who question the occurrence of cancer and the underlying causes. Clinicians may identify cancer clusters when they question the unusual occurrence of a rare form of cancer within their practice or community. In addition, clinicians may be asked to discuss cancer clusters and inform local debates. In this paper, we describe the public health practice experience with cancer clusters and identify cancer prevention and control opportunities for clinicians and public health officials. Scientific investigations of cancer clusters rarely uncover new knowledge about the causes of cancer. However, a set of common characteristics, unique to etiologic cluster investigations have uncovered new information about the causes of cancer or demonstrated a preventable link to a known carcinogen. These characteristics may provide useful clues for sorting out the small number of clusters worthy of further scientific investigation. Public awareness of cancer clusters may promote an opportunity to inform and motivate people about the preventable causes of cancer and effective cancer screening methods.

Organic Mercury Levels among the Yanomama of the Brazilian Amazon Basin

Abstract The Catrimani River basin in northern Brazil is the home of the Yanomama and has been the site of renegade gold mining since 1980. Gold-mining operations release inorganic mercury (Hg) into the environment where it is organified and biomagnified in aquatic ecosystems. Ingestion of mercury-contaminated fish poses a potential hazard to fish-eating populations such as the Yanomama. We surveyed Hg levels in Yanomama villagers living near mined and unmined rivers in 1994 and 1995, and analyzed Hg levels in piranha caught by villagers. In 1994, 90 Yanomama Indians from 5 villages and in 1995, 62 Yanomama Indians from 3 villages participated in the studies. Four villages surveyed in 1994 were located directly on the Catrimani River, approximately 140–160 km downstream from past gold-mining activities. The other village surveyed in 1994 was situated on the unmined Ajaraní River. In 1995, 2 of the Catrimani River villages were revisited, and a third Yanomama village, on the unmined Pacu River, was surveyed. Blood organic mercury levels among all villagers surveyed ranged from 0 to 62.6 µg L–1 (mean levels in each village between 21.2 µg L–1 and 43.1 µg L–1). Mercury levels in piranha from the mined Catrimani River ranged from 235 to 1084 parts per billion (ppb). Nine of 13 piranhas, measuring 30 cm or longer had total mercury levels which exceeded mercury consumption limits (500 ppb) set by both the World Health Organization and the Brazilian Ministry of Health. Unexpectedly, high mercury levels were also observed in fish and villagers along the unmined Ajaraní and Pacu Rivers suggesting that indirect sources may contribute to environmental mercury contamination in the Amazon basin.

Mortality and Morbidity Patterns Associated with the October 12, 1992 Egypt Earthquake

On October 12, 1992, the metropolitan area of Cairo, Egypt and surrounding villages in the Nile Valley sustained the effects of a moderate earthquake of magnitude M B 5.9 (M S 5.2). To identify mortality- or injury-prevention strategies for communities at risk, we investigated deaths and injuries that were associated with the event and modeled the time that patients spent in the hospital because of earthquake-related injuries. Populations in areas closest to the epicenter experienced increased death and injury rates (4.6 deaths per 100,000 and 80.6 injuries per 100,000) compared to those located further from the epicenter (0.8 deaths per 100,000 and 23.7 injuries per 100,000). The distribution of earthquake-related admissions in one hospital peaked within 36 hours after the earthquake. A general linear model predicted that older people were hospitalized longer than younger people and people with fractures to the trunk were hospitalized longer than those with injuries at other anatomical sites (p = 0.008). While recognizing that other characteristics are also important, we recommend that emergency managers consider proximity to the epicenter when planning response operations, and that health officials focus on ensuring appropriate medical care for older people and for people who have suffered severe injuries to the trunk.

Challenges in investigating the association between Agent Orange and cancer: Site‐specific cancer risk and accuracy of exposure assessment

The US military in Vietnam removed vegetative cover near base camps, uncovered enemy forces hiding in thick forests, and destroyed food crops available to enemy forces by spraying herbicides, often by aircraft. One mixture, Agent Orange, contained 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Individuals involved in mixing, spraying, maintaining, and storing Agent Orange and the other herbicide formulations containing 2,4,5-T were exposed to TCDD. Those who may have been exposed include individuals who contacted herbicide-sprayed vegetation or ingested herbicide-contaminated food or water. This included annually more than 850,000 personnel supporting the Republic of Vietnam, including 36,000 Republic of Korea troops. The true number of personnel from either side of the conflict and noncombatant Vietnamese actually exposed to TCDD, and the amount of their exposures, remains unknown. In this issue of Cancer, Yi and Ohrr analyzed cancer incidence among Korean veterans of the Vietnam War (Korean veterans). They compared cancer risk from 1992 through 2003 across Agent Orange exposure categories determined by a model using time and proximity of military units to geographic spray patterns. The findings add to our overall understanding of the health risks from exposures to Agent Orange. Large numbers of individuals were potentially exposed to Agent Orange in Vietnam and this report reminds us of the critical importance of accurate exposure assessment and the desire for epidemiologic studies to provide scientific clarity, even in the most difficult of circumstances. This is the third report of the cancer experience of Korean veterans. In 2011, Yi and Ohrr reported cause-specific mortality for a cohort of 186,760 veterans (19,124 deaths) during the years 1992 through 2005 and compared it with the age-adjusted national mortality rates for Korean males using standardized mortality ratios (SMRs). In 2013, using the Korean National Cancer Incidence Database to identify cases and calculate national male age-adjusted cancer-specific incidence rates and standardized incidence ratios (SIRs), Yi released an analysis of cancer incidence from 1992 through 2003 among 185,265 veterans (9058 cancer cases). The current report used a subset of the previously identified incident cancers (8592 cancer cases) and calculated age-adjusted hazards ratios (HRs) for 180,251 veterans based on 2 qualitative TCDD exposure classifications (high vs low and no, low, moderate, and high exposure). The evidence of an association between TCDD exposure and site-specific cancers is inconsistent across the reports concerning Korean veterans. The new analysis demonstrated significantly elevated HRs among the high-exposure group for mouth, salivary, stomach, small intestine, and all cancers combined, with borderline elevations noted for liver and lung and bronchus cancers. The authors reported that statistically significant increases in cancer risk occurred across the 4 qualitative exposure categories for all cancers and cancers of the salivary gland, small intestine, and liver, but acknowledged that the increases in site-specific cancer risk are neither monotonic nor greatest in the highest exposure classification. By contrast, the observed incident and fatal cancers for the mouth, salivary gland, and stomach were below the number expected

Vigilancia de la salud pública después de una erupción volcánica: lecciones aprendidas en Cerro Negro, Nicaragua, 1992

La erupcion del volcan Cerro Negro cerca de Leon, Nicaragua, el 9 de abril de 1992 lanzo alrededor de 1,7 millones de toneladas de ceniza en una zona de 200 km². Se efectuo una evaluacion inicial de los efectos en la salud de cerca de 300 000 residentes, con los datos normalmente obtenidos mediante el sistema nacional de vigilancia epidemiologica. Se determino que el numero de consultas a los establecimientos de atencion de salud por diarrea e infecciones respiratorias agudas (IRA) aumento en las dos comunidades estudiadas, una dentro de la zona del desastre y otra en sus cercanias. En particular, las consultas por diarrea aguda fueron casi 6,0 veces mas numerosas que antes de la erupcion en ambas comunidades y las consultas por IRA, 3,6 veces mas frecuentes en Malpaisillo (la comunidad cercana a la zona del desastre) y 6,0 veces mas frecuentes en Telica (la comunidad situada dentro de esa zona). Casi todas fueron consultas por enfermedad en lactantes y ninos menores de 5 anos. El aumento de la tasa de morbilidad por diarrea, que frecuentemente se produce despues de las erupciones volcanicas, exige que se investiguen detalladamente el tipo y la calidad del abastecimiento de agua despues de una acumulacion cuantiosa de ceniza. Es preciso examinar con mayor detenimiento los problemas respiratorios asociados con la ceniza para determinar el espectro de esas enfermedades y el momento en que se presentan en lactantes y otros subgrupos especiales de la poblacion. Los datos acopiados por medio de la vigilancia pasiva sobre las condiciones de salud antes y despues de una erupcion pueden emplearse para detectar la morbilidad relacionada con la erupcion. Los sistemas que ya estan establecidos, como el sistema nacional de vigilancia epidemiologica de Nicaragua, se pueden modificar o ampliar para mejorar su sensibilidad a nuevos casos y, por ende, su capacidad de ofrecer servicios de notificacion apropiados a los organismos de socorro medico.