Exposure to Tobacco Smoke and Temperament among U.S. Children 0-5 Years Old

Is secondhand smoke associated with mental health issues? A narrative review of the evidence and policy implications

Secondhand smoke (SHS) is a well-established cause of lung cancer, respiratory disease, heart disease and developmental issues in children, with an overwhelming evidence base spanning over four decades. In this narrative review, we describe studies which have also linked self-reported or cotinine-assessed SHS exposure in the home, workplace and other settings to mental health disorders including depression, suicide, anxiety, and psychological distress in children and adults, sleeping disorders, Attention Deficit Hyperactivity Disorder and behavioural issues in children, and dementia in older adults. In general, evidence indicates that SHS exposure is associated with these disorders in a dose-response manner, with higher odds reported in people who are exposed to SHS at high levels, frequently, and in the home environment. Most studies so far are cross-sectional albeit in large, nationally representative samples from various countries with a smaller number of longitudinal studies. More research is needed in this area to determine whether SHS is a direct cause of adverse mental health outcomes, and whether creating smokefree environments leads to improved mental wellbeing. In particular, more research is needed on the impact of smokefree home environments, an area which has received relatively little focus in smokefree interventions which generally target public places.

Disparities in Toxic Chemical Exposures and Associated Neurodevelopmental Outcomes: A Scoping Review and Systematic Evidence Map of the Epidemiological Literature

BACKGROUND

Children are routinely exposed to chemicals known or suspected of harming brain development. Targeting Environmental Neuro-Development Risks (Project TENDR), an alliance of > 50 leading scientists, health professionals, and advocates, is working to protect children from these toxic chemicals and pollutants, especially the disproportionate exposures experienced by children from families with low incomes and families of color.

OBJECTIVE

This scoping review was initiated to map existing literature on disparities in neurodevelopmental outcomes for U.S. children from population groups who have been historically economically/socially marginalized and exposed to seven exemplar neurotoxicants: combustion-related air pollution (AP), lead (Pb), mercury (Hg), organophosphate pesticides (OPs), phthalates (Phth), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs).

METHODS

Systematic literature searches for the seven exemplar chemicals, informed by the Population, Exposure, Comparator, Outcome (PECO) framework, were conducted through 18 November 2022, using PubMed, CINAHL Plus (EBSCO), GreenFILE (EBSCO), and Web of Science sources. We examined these studies regarding authors' conceptualization and operationalization of race, ethnicity, and other indicators of sociodemographic and socioeconomic disadvantage; whether studies presented data on exposure and outcome disparities and the patterns of those disparities; and the evidence of effect modification by or interaction with race and ethnicity.

RESULTS

Two hundred twelve individual studies met the search criteria and were reviewed, resulting in 218 studies or investigations being included in this review. AP and Pb were the most commonly studied exposures. The most frequently identified neurodevelopmental outcomes were cognitive and behavioral/psychological. Approximately a third (74 studies) reported investigations of interactions or effect modification with 69% (51 of 74 studies) reporting the presence of interactions or effect modification. However, less than half of the studies presented data on disparities in the outcome or the exposure, and fewer conducted formal tests of heterogeneity. Ninety-two percent of the 165 articles that examined race and ethnicity did not provide an explanation of their constructs for these variables, creating an incomplete picture.

DISCUSSION

As a whole, the studies we reviewed indicated a complex story about how racial and ethnic minority and low-income children may be disproportionately harmed by exposures to neurotoxicants, and this has implications for targeting interventions, policy change, and other necessary investments to eliminate these health disparities. We provide recommendations on improving environmental epidemiological studies on environmental health disparities. To achieve environmental justice and health equity, we recommend concomitant strategies to eradicate both neurotoxic chemical exposures and systems that perpetuate social inequities. https://doi.org/10.1289/EHP11750.

Associations of household tobacco smoking status with childhood temperament among U.S. preschool-aged children

BACKGROUND

This study investigated the association between household tobacco smoking status and temperament among U.S. 3-5-year-olds.

METHODS

A secondary analysis of 2019-2020 National Survey of Children's Health data (N = 11,100) was conducted. Temperament dimensions of effortful control (characterized by attention focusing), negative affectivity (characterized by anger and soothability), and surgency (characterized by activity level and shyness) were assessed. Weighted ordinal regression models were conducted while adjusting for child and family covariates.

RESULTS

Approximately 13 % of children lived with smokers. Compared to children who did not live with smokers, children living with smokers displayed behaviors of poorer effortful control and were more likely to be easily distracted (AOR = 1.59, 95%CI = 1.24-2.04) and less likely to keep working on tasks until finished (AOR = 0.56, 95%CI = 0.44-0.71). Children living with smokers displayed behaviors of greater negative affectivity and were at increased odds of being angry or anxious when transitioning between activities (AOR = 1.50, 95%CI = 1.13-1.98) and losing their temper when things did not go their way (AOR = 1.53, 95%CI = 1.20-1.96), and were at decreased odds of calming down quickly when excited (AOR = 0.54, 95%CI = 0.42-0.70). Children living with smokers displayed behaviors of poorer surgency and were less likely to play well with others (AOR = 0.58, 95%CI = 0.45-0.76) and sit still compared to same-aged children (AOR = 0.56, 95%CI = 0.44-0.71).

LIMITATIONS

The NSCH uses a cross-sectional survey design; longitudinal associations and objective measures could not be assessed. However, the NSCH is nationally representative and results are generalizable to U.S. 3-5-year-olds.

CONCLUSIONS

Findings suggest household tobacco smoking influences temperament in early childhood. Results signify the need to promote household tobacco cessation.

Assessment of passive human exposure to tobacco smoke by environmental and biological monitoring in different public places in Wuhan, central China

Passive exposure to tobacco smoke is a global public health problem, while there are few data on public place monitoring and general population exposure assessment in central China. This study aimed to examine the levels of airborne nicotine (n = 256) in ten kinds of different public places in Wuhan, central China, and assess short-term and long-term smoke exposure in 340 non-smokers aged 18-67 who worked in these public places using tobacco biomarkers [i.e., cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), respectively]. The highest median concentration of airborne nicotine (17.0 μg/m³) was observed in internet cafes, approximately 304-fold of the lowest value found in nurseries (55.9 ng/m³). Among the other studied public places, restaurants had the highest median concentrations (ng/m³) of airborne nicotine (3,120), followed by subway stations (810), hotels (624), government officess (286), middle schools (269), health institutions (268), public institutions (190), and primary schools (140). Urinary cotinine and NNAL were found in almost all the participants, and the highest concentrations were found in non-smokers from the internet cafes [specific gravity (SG)-corrected urinary median concentrations: 23.1 ng/mL, geometric mean (GM): 24.1 ng/mL, range: 0.62-1679 ng/mL] for cotinine and 104 pg/mL (GM: 97.6 pg/mL, range: 32.3-236 pg/mL) for NNAL, respectively]. Urinary cotinine concentrations in male non-smokers (median: 2.02 ng/mL) were significantly higher than those in female non-smokers (1.44) (P < 0.01). Participants aged 18-27 were detected with the highest urinary cotinine and NNAL concentrations. Urinary cotinine and NNAL concentrations were significantly correlated with daily and monthly working hours, respectively. Besides, a positive correlation was observed between log-transformed urinary concentrations of cotinine and NNAL (r = 0.32, P < 0.001). This is the first time to report matched data on airborne nicotine and urinary cotinine/NNAL among employees in different public places. This study demonstrated ubiquitous exposure to environmental tobacco smoke in the studied public places.