Positive and negative ions by air purifier have no effects on embryo-fetal development in rats

Yamamoto, Daisuke; Wako, Kiyoshi; Sato, Yukari; Fujishiro, Mayumi; Matsuura, Ikuo; Ohnishi, Yasuyuki

doi:10.2131/jts.39.447

Cited by 4 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the second study, Takasawa et al [ 120 ], investigated whether air ions at ion densities of 1.4, 5.6, and 7.5 million ions/cm 3 can damage the DNA of cells in the lung or blood obtained from rats and mice. A concern for this study, like that of two recent studies from Japan discussed above [ 115 , 116 ], is that the rats were simultaneously exposed to negative and positive air ions at similar levels and this suggests that the resulting concentrations of air ions could be expected to be much lower than reported because of the rapid neutralization of charge by ions of opposite polarity. Damage to DNA is relevant to cancer because damaged DNA, if not repaired by cellular repair mechanisms, can lead to the development of cells with aberrant growth.…”

Section: Resultsmentioning

confidence: 94%

“…Finally, two more recent studies from Japan studied perinatal development. Yamamoto et al reported that the maternal body weight, food consumption, uterine weight, as well as the bone development of male and female offspring of rats exposed to high levels of air ions (8500,000 ions/cm 3 ) at both polarities for the first 20 days of pregnancy were no different from those of sham-exposed controls [ 115 ]. The second study from the same laboratory performed a similar experiment but studied the second-generation offspring as well [ 116 ].…”

Section: Resultsmentioning

confidence: 99%

“…2 f). Because these two studies from Japan exposed animals to both positive and negative ions simultaneously [ 115 , 116 ] these were not plotted in Fig. 2 f with the rest of the studies that reported primary exposures to just one polarity of ion.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Exposure of laboratory animals to small air ions: a systematic review of biological and behavioral studies

2018

View full text Add to dashboard Cite

BackgroundAir ions are molecules of air that have become ionized—that is, they have either lost or gained an electrical charge. Past speculation has suggested that exposure to positive air ions may be harmful to one’s health, while exposure to negative air ions may be associated with beneficial health effects. Air ions arise from natural sources as well as direct-current transmission lines and commercial ionizers. Several recent clinical studies have suggested therapeutic effects of air ions on various types of depression at exposure levels 10- to 1000-fold higher than most previous human studies. The aim of this study was to assess the evidence from studies of laboratory animals for beneficial or adverse effects of air ions on health.MethodsSixty-two studies (1935–2015) in nine topics areas were evaluated for quality and potential systematic bias by ARRIVE guidelines. Standardized mean differences or proportional differences between exposed and control groups were computed for 44 studies to quantitatively assess the strength of the evidence for exposure-related effects.ResultsMany of the studies were conducted before 1990 and exhibited various reporting and methodological deficiencies, including small sample size, failure to control for the influence of potential confounding variables, lack of randomized assignment to treatment groups and blinded analyses, and statistical errors relating to treating group-exposed animals as individuals. The highest quality studies consistently reported no effects of exposure on any of the endpoints examined. There were no evident dose–response relationships within or across studies.ConclusionsExperimental studies of laboratory animals exposed to positive and negative air ions for minutes to years over a five-log unit range of intensities did not suggest any consistent or reliable effects on measures of behavior, learning and memory, neurotransmitters, tracheal function, respiratory infection, cardiovascular function, reproduction and growth, carcinogenesis, or other health endpoints. These data do not provide evidence of adverse or beneficial effects of air ion exposure on health, and did not suggest any biological mechanism of interaction, except perhaps for mechanosensory stimulation of body surfaces by static electric fields at high air ion concentrations.Electronic supplementary materialThe online version of this article (10.1186/s12938-018-0499-z) contains supplementary material, which is available to authorized users.

show abstract

Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Exposure of laboratory animals to small air ions: a systematic review of biological and behavioral studies

2018

View full text Add to dashboard Cite

show abstract

“… NAIs exposure had no effect on the levels of epinephrine, norepinephrine, blood lactic acid, and aerobic metabolism. Yamamoto D/ 2014 d Twenty female pregnant SD rats were randomly divided into two groups. 0, 7.0 × 10 6 ions/cm 3 NAIs, 6 h/day, 20 consecutive days.…”

Section: Literature Search and Study Identificationmentioning

confidence: 99%

Biological effects of negative air ions on human health and integrated multiomics to identify biomarkers: a literature review

Xiao

Wei

Petersen

et al. 2023

Environ Sci Pollut Res

View full text Add to dashboard Cite

Environmental pollution seriously affects human health. The concentration of negative air ions (NAIs), which were discovered at the end of the nineteenth century, is one of the factors used to evaluate air quality. Additionally, NAIs have been widely considered markers by scholars due to their unique biological function. The aim of this study was to summarize existing research and propose future research on the generation and temporal and spatial dynamic patterns of NAIs concentrations as well as the relationship between NAIs and human health. We identified 187 studies (published January 2013–January 2023) that met our inclusion criteria. Fourteen English studies evaluated the effects of NAIs on depression, the cardiovascular system, the respiratory system, reproduction and development, cognition, and sports muscle injury. Only two studies reported the associations of NAIs exposure with metabolic omics. NAIs concentrations vary temporally with solar radiation, air temperature, and relative humidity, while the temporal dynamic patterns of NAIs are affected by season, time, meteorological factors, air quality index, geographical location, forest vegetation, and other factors. Researchers have shown that exposure to NAIs may benefit our health by changing amino acid metabolism, which mainly manifests as increased anti-inflammation and reduced inflammation and antioxidation. Furthermore, exposure to NAIs promotes energy production, affects the expression of c-fos, and regulates 5-HT levels. There has been considerable interest in the potential effects of NAIs on human health and well-being, but the conclusions have been inconsistent and the mechanisms remain unclear. The use of omics to elucidate the biological mechanism of NAIs is relatively new and has some advantages. Graphical Abstract

show abstract

“…Associated with the expanded use of air purifiers in various locations, there is also an increase in the chance for young people giving birth to the next generation to be exposed to ions generated from these devices. In reproductive and developmental toxicity studies in animal models, only "no adverse effects on dams and embryo-fetal development (Yamamoto et al, 2014)" have been reported. Therefore, it is important to assess the reproductive and developmental toxicity of air containing positive and negative ions.…”

Section: Introductionmentioning

confidence: 99%

Positive and negative ions by air purifier have no effects on reproductive function or postnatal growth and development in rats

Yamamoto

Wako

Kumabe

et al. 2015

Fundam. Toxicol. Sci.

Self Cite

View full text Add to dashboard Cite

Air purifiers, which release positive and negative ions generated by electric discharge, are widely used in a variety of places. In this study, male and female SD rats [Crl:CD(SD)] were exposed by whole-body inhalation (6 hr/day) to ionized air containing positive and negative ions for at least 10 weeks before mating and throughout the mating, gestation, and lactation periods over two generations, and the effects on the reproductive function of parental animals and development of offspring were assessed. The concentrations of the ionized air were set at 0 and 7,000,000 ions/cm 3 (280-to 1,000-fold higher than normally used in humans) and each group consisted of 24 F0 rats/sex/group and 20 to 23 F1 rats/sex/group. The ionized air had no general toxicological effects on parental animals in the observation for clinical signs, body weight and food consumption measurement, or pathological examination. As for the effects on the reproductive function, there were no exposure-related changes in mating ability, fertility, pregnancy, parturition, or nursing behavior, nor were there any changes in the estrous cycle or sperm parameters in either generation, nor in the ovarian follicle counts (only F1 females). Moreover, there were no effects on litter size, viability, growth, or development of F1 and F2 offspring, including sexual maturation. Therefore, it was suggested that the ionized air has no reproductive or developmental toxicity in rats.

show abstract

Positive and negative ions by air purifier have no effects on embryo-fetal development in rats

Cited by 4 publications

References 7 publications

Exposure of laboratory animals to small air ions: a systematic review of biological and behavioral studies

Exposure of laboratory animals to small air ions: a systematic review of biological and behavioral studies

Biological effects of negative air ions on human health and integrated multiomics to identify biomarkers: a literature review

Positive and negative ions by air purifier have no effects on reproductive function or postnatal growth and development in rats

Contact Info

Product

Resources

About