Co-sleeping with pets, stress, and sleep in a nationally-representative sample of United States adults.

This cross-sectional study tested the direct and stress-buffering effects of co-sleeping with pets on human sleep characteristics in a nationally-representative sample of United States adults. Participants completed questionnaires assessing their sleep characteristics, including perceived sleep quality, perceived sleep efficiency, insomnia severity, and multidimensional sleep health. We evaluated whether co-sleeping with pets was associated with sleep characteristics and whether co-sleeping with pets moderated the association of stress and sleep characteristics. Exploratory analyses examined whether sleep characteristics were impacted by number of pets, pet type, and bondedness to pets. Our final sample of 1591 participants (Mage = 46.4 years, SD = 17.5; 56% female; 76% White) included 758 participants who reported co-sleeping with pets (47.6%). Co-sleeping with pets was associated with poorer sleep characteristics-specifically, poorer perceived sleep quality and greater insomnia severity. Although higher levels of stress were associated with poorer sleep, we did not observe evidence for a stress-buffering effect of co-sleeping with pets. Exploratory analyses indicated that the negative impact of co-sleeping with pets on human sleep was associated with dog ownership but not cat ownership, more pronounced when individuals own a greater number of pets, and not impacted by bondedness to pets. Our findings contribute to emerging evidence for the impact of co-sleeping with pets on human sleep. Study was pre-registered at: https://aspredicted.org/3VN_WF6 .

Generation of microplastics from the opening and closing of disposable plastic water bottles.

There has recently been a significant increase in interest regarding the prevalence of microplastics in bottled water. Previous studies have shown that the composition of many of the microplastics in bottled water is consistent with the materials of the bottle and bottle cap. The focus of this study is to quantify microplastic particle generation from the cap and bottle interaction during open and close cycles. Nile Red dye was used for the detection of microplastics >4.7 µm in size. Microplastic contamination levels in the water were found to increase as the bottle cap is opened and closed repeatedly. The rate of generation of particles with bottle opening and closing cycles (553 ± 202 microplastics/L/cycle) is adequate to account for the total particle density in the water. This clearly demonstrates that the abrasion between the bottle cap and bottleneck is the dominant mechanism for the generation of microplastic contamination detected in bottled water. A large spread between the maximum and minimum levels of microplastic contamination for bottles from the same lot, regardless of the number of times the cap is opened and closed, suggests that mechanical tolerances in the manufacturing of bottles and caps might play an important role in microplastic generation.