Do Carpets Impair Indoor Air Quality and Cause Adverse Health Outcomes: A Review

Several earlier studies have shown the presence of more dust and allergens in carpets compared with non-carpeted floors. At the same time, adverse effects of carpeted floors on perceived indoor air quality as well as worsening of symptoms in individuals with asthma and allergies were reported. Avoiding extensive carpet use in offices, schools, kindergartens and bedrooms has therefore been recommended by several health authorities. More recently, carpet producers have argued that former assessments were obsolete and that modern rugs are unproblematic, even for those with asthma and allergies. To investigate whether the recommendation to be cautious with the use of carpets is still valid, or whether there are new data supporting that carpet flooring do not present a problem for indoor air quality and health, we have reviewed the literature on this matter. We have not found updated peer reviewed evidence that carpeted floor is unproblematic for the indoor environment. On the contrary, also more recent data support that carpets may act as a repository for pollutants which may become resuspended upon activity in the carpeted area. Also, the use of carpets is still linked to perception of reduced indoor air quality as well as adverse health effects as previously reported. To our knowledge, there are no publications that report on deposition of pollutants and adverse health outcomes associated with modern rugs. However, due to the three-dimensional structure of carpets, any carpet will to some extent act like a sink. Thus, continued caution should still be exercised when considering the use of wall-to-wall carpeted floors in schools, kindergartens and offices, as well as in children’s bedrooms unless special needs indicate that carpets are preferableAcknowledgments: This study has not received any funding or grants. NIPH cover the costs for publishing in open access.publishedVersio

Inflammatory effects of exposure to different stone types used in Norwegian asphalt

During the winter in Scandinavian countries, up to 90% of traffic-related particulate matter (PM) is from non-exhaust emissions sources such as asphalt wear. Measures to reduce urban PM have focused mainly on exhaust emissions, while the contribution from asphalt has received less attention. In vitro studies suggest that the composition of asphalt can affect the inflammatory potential of road dust. Using a whole-body human exposure chamber, we have explored whether different stone materials used in Norwegian asphalt impose different inflammatory reactions in plasma of healthy volunteers. Our results show no acute increases in the inflammatory markers SP-D, P- selectin, or CC16. However, quartz diorite induced an apparent increase in ICAM-1, not seen for rhomb porphyry or placebo dust (lactose). Although this did not reach statistical significance, it resembles previously observed fibrinogen-effects, and may suggest that different types of stone minerals provoke different inflammatory reactions in humans compared to placebo dust.publishedVersio

Respirable stone particles differ in their ability to induce cytotoxicity and pro-inflammatory responses in cell models of the human airways

Background Respirable stone- and mineral particles may be a major constituent in occupational and ambient air pollution and represent a possible health hazard. However, with exception of quartz and asbestos, little is known about the toxic properties of mineral particles. In the present study, the pro-inflammatory and cytotoxic responses to six stone particle samples of different composition and with diameter below 10 μm were assessed in human bronchial epithelial cells (HBEC3-KT), THP-1 macrophages and a HBEC3-KT/THP-1 co-culture. Moreover, particle-induced lysis of human erythrocytes was assessed to determine the ability of the particles to lyse biological membranes. Finally, the role of the NLRP3 inflammasome was assessed using a NLRP3-specific inhibitor and detection of ASC oligomers and cleaved caspase-1 and IL-1β. A reference sample of pure α-quartz was included for comparison. Results Several stone particle samples induced a concentration-dependent increase in cytotoxicity and secretion of the pro-inflammatory cytokines CXCL8, IL-1α, IL-1β and TNFα. In HBEC3-KT, quartzite and anorthosite were the most cytotoxic stone particle samples and induced the highest levels of cytokines. Quartzite and anorthosite were also the most cytotoxic samples in THP-1 macrophages, while anorthosite and hornfels induced the highest cytokine responses. In comparison, few significant differences between particle samples were detected in the co-culture. Adjusting responses for differences in surface area concentrations did not fully account for the differences between particle samples. Moreover, the stone particles had low hemolytic potential, indicating that the effects were not driven by membrane lysis. Pre-incubation with a NLRP3-specific inhibitor reduced stone particle-induced cytokine responses in THP-1 macrophages, but not in HBEC3-KT cells, suggesting that the effects are mediated through different mechanisms in epithelial cells and macrophages. Particle exposure also induced an increase in ASC oligomers and cleaved caspase-1 and IL-1β in THP-1 macrophages, confirming the involvement of the NLRP3 inflammasome. Conclusions The present study indicates that stone particles induce cytotoxicity and pro-inflammatory responses in human bronchial epithelial cells and macrophages, acting through NLRP3-independent and -dependent mechanisms, respectively. Moreover, some particle samples induced cytotoxicity and cytokine release to a similar or greater extent than α-quartz. Thus, these minerals warrant further attention in future research.publishedVersio

Oxidative potential versus biological effects: A review on the relevance of cell-free/abiotic assays as predictors of toxicity from airborne particulate matter

Background and Objectives: The oxidative potential (OP) of particulate matter (PM) in cell-free/abiotic systems have been suggested as a possible measure of their biological reactivity and a relevant exposure metric for ambient air PM in epidemiological studies. The present review examined whether the OP of particles correlate with their biological effects, to determine the relevance of these cell-free assays as predictors of particle toxicity. Methods: PubMed, Google Scholar and Web of Science databases were searched to identify relevant studies published up to May 2019. The main inclusion criteria used for the selection of studies were that they should contain (1) multiple PM types or samples, (2) assessment of oxidative potential in cell-free systems and (3) assessment of biological effects in cells, animals or humans. Results: In total, 50 independent studies were identified assessing both OP and biological effects of ambient air PM or combustion particles such as diesel exhaust and wood smoke particles: 32 in vitro or in vivo studies exploring effects in cells or animals, and 18 clinical or epidemiological studies exploring effects in humans. Of these, 29 studies assessed the association between OP and biological effects by statistical analysis: 10 studies reported that at least one OP measure was statistically significantly associated with all endpoints examined, 12 studies reported that at least one OP measure was significantly associated with at least one effect outcome, while seven studies reported no significant correlation/association between any OP measures and any biological effects. The overall assessment revealed considerable variability in reported association between individual OP assays and specific outcomes, but evidence of positive association between intracellular ROS, oxidative damage and antioxidant response in vitro, and between OP assessed by the dithiothreitol (DDT) assay and asthma/wheeze in humans. There was little support for consistent association between OP and any other outcome assessed, either due to repeated lack of statistical association, variability in reported findings or limited numbers of available studies. Conclusions: Current assays for OP in cell-free/abiotic systems appear to have limited value in predicting PM toxicity. Clarifying the underlying causes may be important for further advancement in the field

Oxidative potential versus biological effects: A review on the relevance of cell-free/abiotic assays as predictors of toxicity from airborne particulate matter

Background and Objectives: The oxidative potential (OP) of particulate matter (PM) in cell-free/abiotic systems have been suggested as a possible measure of their biological reactivity and a relevant exposure metric for ambient air PM in epidemiological studies. The present review examined whether the OP of particles correlate with their biological effects, to determine the relevance of these cell-free assays as predictors of particle toxicity. Methods: PubMed, Google Scholar and Web of Science databases were searched to identify relevant studies published up to May 2019. The main inclusion criteria used for the selection of studies were that they should contain (1) multiple PM types or samples, (2) assessment of oxidative potential in cell-free systems and (3) assessment of biological effects in cells, animals or humans. Results: In total, 50 independent studies were identified assessing both OP and biological effects of ambient air PM or combustion particles such as diesel exhaust and wood smoke particles: 32 in vitro or in vivo studies exploring effects in cells or animals, and 18 clinical or epidemiological studies exploring effects in humans. Of these, 29 studies assessed the association between OP and biological effects by statistical analysis: 10 studies reported that at least one OP measure was statistically significantly associated with all endpoints examined, 12 studies reported that at least one OP measure was significantly associated with at least one effect outcome, while seven studies reported no significant correlation/association between any OP measures and any biological effects. The overall assessment revealed considerable variability in reported association between individual OP assays and specific outcomes, but evidence of positive association between intracellular ROS, oxidative damage and antioxidant response in vitro, and between OP assessed by the dithiothreitol (DDT) assay and asthma/wheeze in humans. There was little support for consistent association between OP and any other outcome assessed, either due to repeated lack of statistical association, variability in reported findings or limited numbers of available studies. Conclusions: Current assays for OP in cell-free/abiotic systems appear to have limited value in predicting PM toxicity. Clarifying the underlying causes may be important for further advancement in the field

G-protein coupled receptors (GPCR) and environmental exposure. Consequences for cell metabolism using the β-adrenoceptors as example

International audienceThe impact of endocrine disruptors (EDs), compounds disturbing the normal action of hormones, represents a major field of toxicological research, in particular through the interference with steroid hormones and their nuclear receptors. By contrast, G-protein coupled receptors (GPCRs) have been a major focus of pharmacological research and drug-development, but have received limited attention in toxicology as potential targets of EDs. In this review we discuss the potential importance of GPCRs in the mode of action of EDs, using the recently observed interaction between polycyclic aromatic hydrocarbons (PAHs) and β-adrenergic receptors as an example. This ability to disturb adrenoceptor function represent a novel mode of action (MOA) for hormone disruption by EDs which may affect both metabolic processes and immune responses. The outcome may be of relevance to development or exacerbation of multifactorial non-communicable diseases (NCDs)

Dampness and Moisture Problems in Norwegian Homes

The occurrence of dampness and mold in the indoor environment is associated with respiratory-related disease outcomes. Thus, it is pertinent to know the magnitude of such indoor environment problems to be able to estimate the potential health impact in the population. In the present study, the moisture damage in 10,112 Norwegian dwellings was recorded based on building inspection reports. The levels of moisture damage were graded based on a condition class (CC), where CC0 is immaculate and CC1 acceptable (actions not required), while CC2 and CC3 indicate increased levels of damage that requires action. Of the 10,112 dwellings investigated, 3125 had verified moisture or mold damage. This amounts to 31% of the surveyed dwellings. Of these, 27% had CC2 as the worst grade, whereas 4% had CC3 as the worst grade level. The room types and building structures most prone to moisture damage were (in rank order) crawl spaces, basements, un-insulated attics, cooling rooms, and bathrooms. The high proportion of homes with moisture damage indicate a possible risk for respiratory diseases in a relatively large number of individuals, even if only the more extensive moisture damages and those located in rooms where occupants spend the majority of their time would have a significant influence on adverse health effectspublishedVersio

Inneklima i skoler og barnehager: Helsemessig betydning for barn og unge

Barn og unge er følsomme grupper med hensyn til eksponering for luftforurensninger. Dette skyldes i stor grad aldersbetingede forskjeller i fysiologi og toksikokinetikk (opptak, fordeling, omdanning og utskillelse) samt eventuelle eksisterende sykdommer og arvelige faktorer. Barn, spesielt de minste, puster også inn mer luft i forhold til kroppsvekt, har større grad av hånd-til-munnkontakt, og er generelt dårligere til å unngå eksponeringssituasjoner. Dette er faktorer som øker den relative eksponeringen for luft og støvbårne forurensninger. Godt inneklima i skoler og barnehager har stor betydning for helse, trivsel og læring for barn og unge. Både befolkningsstudier og toksikologisk/biologisk forskning har vist at flere risikoforhold i inneklimasammenheng kan knyttes til uønskede helseeffekter. Eksempler på slike risikoforhold er fuktproblemer og muggvekst, en del kilder til flyktige organiske forbindelser, høy partikkelforurensning, radon og allergener. De uønskede helseeffektene synes særlig å være knyttet til luftveissykdommer (infeksjoner, astma og luftveisallergi), irritasjon av slimhinner og hodepine. Det gjør det viktig å forebygge og utbedre de risikoforhold som har sterkest sammenheng med helserisiko i inneklimasammenheng. Flere studier har videre vist at uheldige inneklimaforhold knyttet til ventilasjon, temperatur og belysning i skoler og barnehager kan påvirke skoleprestasjoner og arbeidsevne. Selv om vi med dagens kunnskap ikke kan angi eksakte tall for hvor mange som kan bli eller er syke som følge av dårlig inneklima, vet vi nok til å ta barn, unge og inneklima i skoler og barnehager alvorlig. Ut fra de utvalgsundersøkelser som er gjort fremgår det at svært mange skoler i Norge har et dårlig inneklima på grunn av manglende vedlikehold. Eksempelvis er det gjennom Arbeidstilsynets arbeid avdekket at ca halvparten av 301 skoler hadde eller hadde hatt problemer med vannlekkasjer og/eller fuktproblematikk. Utdannings- og helsemyndighetenes kartlegginger av landets skoler i senere tid viser at ca. 900 skoler mangler godkjenning etter regelverket om miljørettet helsevern i barnehager og skoler. Vi mener det er god grunn til å anta at antall barn som opplever uønskede helseutfall, plager og nedsatt trivsel på grunn av dårlig inneklima er relativt høyt. Det er også grunn til å anta at dårlige inneklimaforhold i skoler kan gå ut over barnas skoleprestasjoner. Svært ofte synes inneklimaproblemene i skoler og barnehager å være knyttet til sviktende forvaltning, drift og vedlikehold. Med det vi vet i dag, vil sannsynligvis de fleste inneklimaproblemer kunne reduseres eller unngås helt forutsatt at både samfunnet og enkeltpersoner er villig til å bruke tid og ressurser på dette