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Biomedical subjects

Joshua A Mott

Publications and source records attributed to Joshua A Mott.

9 recordsLinked to original sources

Cardiorespiratory hospitalizations associated with smoke exposure during the 1997, Southeast Asian forest fires.

We investigated the cardiorespiratory health effects of smoke exposure from the 1997 Southeast Asian Forest Fires among persons who were hospitalized in the region of Kuching, Malaysia. We selected admissions to seven hospitals in the Kuching region from a database of all hospital admissions in the state of Sarawak during January 1, 1995 and December 31, 1998. For several cardiorespiratory disease classifications we used Holt-Winters time-series analyses to determine whether the total number of monthly hospitalizations during the forest fire period (August 1 to October 31, 1997), or post-fire period (November 1, 1997 to December 31, 1997) exceeded forecasted estimates established from a historical baseline period of January 1, 1995 to July 31, 1997. We also identified age-specific cohorts of persons whose members were admitted for specific cardiorespiratory problems during January 1 to July 31 of each year (1995--1997). We compared Kaplan-Meier survival curves of time to first readmission for the 1997 cohorts (exposed to the forest fire smoke) with the survival curves for the 1995 and 1996 cohorts (not exposed, pre-fire cohorts). The time-series analyses indicated that statistically significant fire-related increases were observed in respiratory hospitalizations, specifically those for chronic obstructive pulmonary disease (COPD) and asthma. The survival analyses indicated that persons over age 65 years with previous hospital admissions for any cause (chi2(1df) = 5.98, p = 0.015), any cardiorespiratory disease (chi2(1df) = 5.3, p = 0.02), any respiratory disease (chi2(1df) = 7.8, p = 0.005), or COPD (chi2(1df) = 3.9, p = 0.047), were significantly more likely to be rehospitalized during the follow-up period in 1997 than during the follow-up periods in the pre-fire years of 1995 or 1996. The survival functions of the exposed cohorts resumed similar trajectories to unexposed cohorts during the post-fire period of November 1, 1997 to December 31, 1998. Communities exposed to forest fire smoke during the Southeast Asian forest fires of 1997 experienced short-term increases in cardiorespiratory hospitalizations. When an air quality emergency is anticipated, persons over age 65 with histories of respiratory hospitalizations should be preidentified from existing hospitalization records and given priority access to interventions.

Adolescent↗

Assessment of urinary metals following exposure to a large vegetative fire, New Mexico, 2000.

INTRODUCTION: In May 2000, a vegetative fire burned 47,000 acres in northern New Mexico, including 7500 acres of land administered by the Los Alamos National Laboratory. We evaluated potential human exposures from the fire. METHODS: We surveyed two populations (firefighters and the general population) in four cities for urine heavy metal concentrations. Reference concentrations were based on the Third National Health and Nutrition Examination Survey (NHANES III). Multivariate linear regression assessed the association of urinary metal concentrations with smoke exposure. We also performed isotopic analysis of uranium and cesium on a subset of specimens. RESULTS: A total of 92 firefighters and 135 nonfirefighters participated. In both populations, urinary nickel, cesium, chromium, and uranium concentrations were greater than expected compared with NHANES III reference values. No values required immediate medical follow-up. Regression analysis demonstrated that for National Guard members, arsenic and cadmium levels were significantly related to smoke exposure, and for firefighters, cesium and arsenic levels were significantly related to exposure; however, only for cesium in National Guard members was this association in the positive direction. Isotopic analysis demonstrated that the cesium and uranium were naturally occurring. CONCLUSIONS: Some people had spot urine metal concentrations above nationally derived reference values, and values for some metals were associated with smoke exposure. These associations had little public health or clinical importance. Studies of exposures resulting from vegetative fires are difficult, and careful consideration should be given to the technical and communication processes at the outset of a fire exposure investigation. Recommendations for future investigations include testing as soon as possible during or after a fire, and early clinical consultation with a medical toxicologist.

Environmental Exposure↗

National vehicle emissions policies and practices and declining US carbon monoxide-related mortality.

CONTEXT: Carbon monoxide (CO) has been reported to contribute to more than 2000 poisoning deaths per year in the United States. OBJECTIVES: To evaluate the influence of national vehicle emissions policies and practices on CO-related mortality and to describe 31 years (1968-1998) of CO-related deaths in the United States. DESIGN AND SETTING: Longitudinal trend analysis using computerized death data from the Centers for Disease Control and Prevention, US Census Bureau population data, and annual CO emissions estimates for light-duty vehicles provided by the US Environmental Protection Agency. MAIN OUTCOME MEASURE: All deaths in the US for which non-fire-related CO poisoning was an underlying or contributing condition, classified by intent and mechanism of death. Negative binomial regression was used to incorporate every year of data into estimated percentage changes in CO emissions and mortality rates over time. RESULTS: During 1968-1998, CO-related mortality rates in the United States declined from 20.2 deaths to 8.8 deaths per 1 million person-years (an estimated decline of 57.8%; 95% confidence interval [CI], -62.4% to -52.6%). Following the introduction of the catalytic converter to automobiles in 1975, CO emissions from automobiles decreased by an estimated 76.3% of 1975 levels (95% CI, -82.0% to -70.4%) and unintentional motor vehicle-related CO death rates declined from 4.0 to 0.9 deaths per 1 million person-years (an estimated decline of 81.3%; 95% CI, -84.8% to -77.0%). Rates of motor vehicle-related CO suicides declined from 10.0 to 4.9 deaths per 1 million person-years (an estimated decline of 43.3%; 95% CI, -57.5% to -24.3%). During 1975-1996, an annual decrease of 10 g/mile of estimated CO emissions from automobiles was associated with a 21.3% decrease (95% CI, -24.2% to -18.4%) in the annual unintentional motor vehicle-related CO death rate and a 5.9% decrease (95%CI, -10.0% to -1.8%) in the annual rate of motor vehicle-related CO suicides. CONCLUSIONS: If rates of unintentional CO-related deaths had remained at pre-1975 levels, an estimated additional 11 700 motor vehicle-related CO poisoning deaths might have occurred by 1998. This decline in death rates appears to be a public health benefit associated with the enforcement of standards set by the 1970 Clean Air Act.

Accidents↗

The interactive effects of infant activity level and fear on growth trajectories of early childhood behavior problems.

The current study examined the interactive effects of infant activity level and fear on growth trajectories of behavior problems in early childhood (age 4 to 8 years) using maternal ratings. The sample was drawn from the National Longitudinal Survey of Youth (NLSY) and included children who were between 1 and 11 months in 1986. Findings suggested that boys characterized by high activity level and low levels of fear in infancy escalated in both externalizing and internalizing symptoms. Also, boys characterized by high fear and low activity level increased in internalizing symptoms and these effects seemed to be specific to depression rather than anxiety. Temperament did not predict escalation in externalizing symptomatology for girls, but low levels of fear predicted increases in internalizing symptoms. There was also evidence for a decline in depression specific symptoms for girls characterized by high fear and low activity in infancy. These findings suggest the importance of examining interactive models of temperament risk and considering gender specific pathways to behavior problems.

Age Factors↗

Wildland forest fire smoke: health effects and intervention evaluation, Hoopa, California, 1999.

OBJECTIVES: To assess the health effects of exposure to smoke from the fifth largest US wildfire of 1999 and to evaluate whether participation in interventions to reduce smoke exposure prevented adverse lower respiratory tract health effects among residents of the Hoopa Valley National Indian Reservation in northwestern California. DESIGN: Observational study: epidemiologists from the Centers for Disease Control and Prevention retrospectively reviewed medical records at the local medical center and conducted survey interviews of reservation residents. SETTING: Humboldt County, California. PARTICIPANTS: Interviews were completed with 289 of 385 residents, representing 26% of the households on the reservation. Of the 289 participants, 92 (31.8%) had preexisting cardiopulmonary conditions. RESULTS: During the weeks of the forest fire, medical visits for respiratory illnesses increased by 217 visits (from 417 to 634 visits, or by 52%) over the previous year. Survey results indicated that although 181 (62.6%) of 289 participants reported worsening lower respiratory tract symptoms, those with preexisting cardiopulmonary conditions reported more symptoms before, during, and after the smoke episode. An increased duration of the use of high-efficiency particulate air cleaners and the recollection of public service announcements were associated with a reduced odds of reporting adverse health effects of the lower respiratory tract. No protective effects were observed for duration of mask use or evacuation. CONCLUSIONS: Timely actions undertaken by the clinical staff of the local medical center appeared beneficial to the respiratory health of the community. Future programs that reduce economic barriers to evacuation during smoke episodes may also improve intervention participation rates and decrease smoke exposures. Although promising, the effectiveness of these and other interventions need to be confirmed in a prospective community intervention trial.

Adult↗

Call-tracking data and the public health response to bioterrorism-related anthrax.

After public notification of confirmed cases of bioterrorism-related anthrax, the Centers for Disease Control and Prevention's Emergency Operations Center responded to 11,063 bioterrorism-related telephone calls from October 8 to November 11, 2001. Most calls were inquiries from the public about anthrax vaccines (58.4%), requests for general information on bioterrorism prevention (14.8%), and use of personal protective equipment (12.0%); 882 telephone calls (8.0%) were referred to the state liaison team for follow-up investigation. Of these, 226 (25.6%) included reports of either illness clinically confirmed to be compatible with anthrax or direct exposure to an environment known to be contaminated with Bacillus anthracis. The remaining 656 (74.4%) included no confirmed illness but reported exposures to "suspicious" packages or substances or the receipt of mail through a contaminated facility. Emergency response staff must handle high call volumes following suspected or actual bioterrorist attacks. Standardized health communication protocols that address contact with unknown substances, handling of suspicious mail, and clinical evaluation of suspected cases would allow more efficient follow-up investigations of clinically compatible cases in high-risk groups.

Anthrax↗

Sex differences in COPD and lung cancer mortality trends--United States, 1968-1999.

PURPOSE: Cigarette smoking by U.S. women in the 1940s and 1950s caused large increases in smoking-related lung disease among women. To determine the magnitude of these increases, we compared the mortality trends for males and females in the United States for chronic obstructive pulmonary disease (COPD) and lung cancer for 1968-1999. METHODS: We used the national mortality data files compiled by the National Center for Health Statistics of the CDC and U.S. census data to calculate age-adjusted (2000) death rates for COPD, lung cancer, and all causes. RESULTS: COPD death rate for females increased by 382% from 1968 through 1999, whereas for males it increased by 27% during the same period. As a result, the COPD death rate for U.S. females is approaching that for males. The lung cancer death rate for females increased by 266% from 1968 to 1999, whereas for males, it increased by 15%. CONCLUSIONS: Physicians, women, and groups interested in women's health issues need to be aware of these trends and target prevention strategies toward females.

Female↗

Carbon monoxide-related injury estimation using ICD-coded data: methodologic implications for public health surveillance.

Estimates of unintentional deaths from carbon monoxide (CO) poisoning can be obtained from national mortality data. We explored ways of accurately estimating CO-related deaths from International Classification of Diseases, 9th Revision (ICD-9) coded U.S. mortality data. We evaluated and identified CO-related ICD-9 codes and created five classes of codes for case ascertainment that represented a continuum of the degree of certainty that the ICD-coded death was truly CO-related. We conducted single (underlying) cause-of-death and multiple-cause-of-death analysis using 20 years of data (1979-1998), and calculated sensitivity and positive predictive value using different criteria for case ascertainment. Single-cause analysis provided accurate estimates only when we used CO-exclusive E-codes, however this method failed to identify approximately one third of the CO-related deaths over the study period. Single-cause analysis overestimated the number of CO-related deaths when we used E-codes that were not exclusive to CO exposure. Identification of true CO-related deaths required multiple cause-of-death analysis and use of the CO nature-of-injury code, N986, to confirm suspected cases. Sensitivity of N986 was 99.5%, and positive predictive value of the individual E-codes in single cause-of-death analysis ranged from 1.5% to 92%. Estimating CO-related deaths from ICD-coded data requires a thorough understanding of the ICD codes, coding rules, and of the limitations imposed by case selection criteria and single cause-of-death analysis.

Air Pollutants↗