Sleep interruption associated with house staff work schedules alters circadian gene expression.

Background: Epidemiological studies indicate that disruption of circadian rhythm by shift work increases the risk of breast and prostate cancer. Our studies demonstrated that carcinogens disrupt the circadian expression of circadian genes (CGs) and circadian-controlled genes (CCGs) during the early stages of rat mammary carcinogenesis. A chemopreventive regimen of methylselenocysteine (MSC) restored the circadian expression of CGs and CCGs, including PERIOD 2 (PER2) and estrogen receptor β (ERS2), to normal.

A controlled trial of acute effects of human exposure to traffic particles on pulmonary oxidative stress and heart rate variability.

Background: For many individuals, daily commuting activities on roadways account for a substantial proportion of total exposure, as well as peak-level exposures, to traffic-related air pollutants (TRAPS) including ultrafine particles, but the health impacts of these exposures are not well-understood. We sought to determine if exposure to TRAPs particles during commuting causes acute oxidative stress in the respiratory tract or changes in heart rate variability (HRV), a measure of autonomic activity.

Methods: We conducted a randomized, cross-over trial in which twenty-one young adults took two 1.

Controlled exposure to diesel exhaust causes increased nitrite in exhaled breath condensate among subjects with asthma.

Objective: To determine whether oxidative/nitrosative stress plays a role in the acute effects of diesel exhaust (DE) on subjects with asthma.

Methods: In this crossover study, 16 subjects with mild to moderate asthma were exposed to clean filtered air or diluted DE (300 μg/m as PM2.5) for 1 hour with intermittent exercise.

Unique features of obstructive sleep apnea in World Trade Center responders with aerodigestive disorders.

Objectives: To compare obstructive sleep apnea (OSA) in World Trade Center (WTC) responders with aerodigestive disorders and snoring with non-WTC habitual snorers, and to distinguish features of OSA in a subset of responders with worsening of snoring after 9/11 from responders with previous habitual snoring.

Methods: Cross-sectional comparative study of 50 WTC Medical Monitoring and Treatment Program responders with aerodigestive disorders and snoring and 50 nonresponders with snoring. Responders with worsening of snoring after 9/11 were compared with previous habitual snorers.

Sickness response symptoms among healthy volunteers after controlled exposures to diesel exhaust and psychological stress.

Background: Interactions between acute exposures to environmental chemical contaminants and psychological stress may be important in situations where they are likely to co-occur, ranging in intensity from daily urban living to participation in war. Modification of symptomatic responses by stress may play a role in medically unexplained symptoms attributed to low-level chemical exposures.

Objectives: We hypothesized that the combination of exposure to diesel exhaust (DE) and acute psychological stress would cause sickness responses in healthy volunteers.

Quantification of 1-aminopyrene in human urine after a controlled exposure to diesel exhaust.

Diesel exhaust (DE) is a significant source of air pollution that has been linked to respiratory and cardiovascular morbidity and mortality. Many components in DE, such as polycyclic aromatic hydrocarbons, are present in the environment from other sources. 1-Nitropyrene appears to be a more specific marker of DE exposure.

Sensory and cognitive effects of acute exposure to hydrogen sulfide.

Background: Some epidemiologic studies have reported compromised cognitive and sensory performance among individuals exposed to low concentrations of hydrogen sulfide (H2S).

Objectives: We hypothesized a dose-response increase in symptom severity and reduction in sensory and cognitive performance in response to controlled H2S exposures.

Methods: In separate exposure sessions administered in random order over three consecutive weeks, 74 healthy subjects [35 females, 39 males; mean age (+/- SD) = 24.

Negative affect and chemical intolerance as risk factors for building-related symptoms: a controlled exposure study.

Objective: To assess whether differences in negative affect (NA) and chemical intolerance (CI) affect responses to chemical mixtures and stress in a controlled experimental model.

Methods: Participants were 130 nonsmoking, healthy women, recruited from a university community. Participants completed the Positive and Negative Affect Scale and the Chemical Odor Intolerance Index.

Nasal effects of a mixture of volatile organic compounds and their ozone oxidation products.

Objective: Our objective was to determine if low levels of a mixture of volatile organic compounds (VOCs) and their ozone (O3) oxidation products, similar to what might be found in "sick buildings," cause nasal irritation and inflammation under controlled exposure conditions.

Methods: Healthy, nonsmoking women (n=130) completed 2-hour controlled exposures to VOCs, VOCs and O3, and a masked air "MA" control in random order at least 1 week apart. VOCs and O3 concentrations were approximately 25 mg/m and approximately 40 ppb, respectively.

Health effects of a mixture of indoor air volatile organics, their ozone oxidation products, and stress.

In our present study we tested the health effects among women of controlled exposures to volatile organic compounds (VOCs), with and without ozone (O3), and psychological stress. Each subject was exposed to the following three conditions at 1-week intervals (within-subject factor): VOCs (26 mg/m3), VOCs + O3 (26 mg/m3 + 40 ppb), and ambient air with a 1-min spike of VOCs (2.5 mg/m3).

Responses to controlled diesel vapor exposure among chemically sensitive Gulf War veterans.

Objective: A significant proportion of Gulf War veterans (GWVs) report chemical sensitivity, fatigue, and unexplained symptoms resulting in ongoing disability. GWVs frequently recall an association between diesel and petrochemical fume exposure and symptoms during service. The purpose of the present study among GWVs was to evaluate the immediate health effects of acute exposure to chemicals (diesel vapors with acetaldehyde) with and without stress.

Cognitive effects of chronic exposure to lead and solvents.

Background: Occupational exposure to lead and solvents has declined steadily over the past 20 years, however, construction workers continue to be exposed to these neurotoxicants. The purpose of this study was to investigate the cognitive effects of chronic occupational exposure to lead and solvents.

Method: Based on K-XRF of tibial bone lead and occupational history of solvent exposure, subjects were classified into four exposure groups: lead (N = 40), solvent (N = 39), lead/solvent (N = 45), and control (N = 33).

Anxiety sensitivity and depression in multiple chemical sensitivities and asthma.

Patients with sensitivities to multiple chemicals report symptoms of cognitive dysfunction, respiratory distress, and mood disturbance. Lifetime and current psychiatric disorders, personality traits associated with symptom reporting, and tests of cognitive function were compared between 30 subjects with Multiple Chemical Sensitivities (MCS), 19 asthmatics, and 31 healthy controls. Relative to asthmatics and controls, more MCS subjects met criteria for current depression and somatization disorder.