Polychlorinated Biphenyls In Indoor Air Research Articles

Exposure to airborne polychlorinated biphenyls and type 2 diabetes in a Danish cohort

BackgroundPrevious research indicates an association between higher-chlorinated polychlorinated biphenyls (PCBs) and type 2 diabetes (T2D). However, less is known about the extent to which PCB exposure in indoor air, composed primarily of lower-chlorinated PCBs, affects T2D risk. We assessed the association between indoor air exposure to PCBs in residential buildings and T2D incidence. MethodsThe register-based ‘Health Effects of PCBs in Indoor Air’ (HESPAIR) cohort comprises 51,921 Danish residents of two residential areas with apartments built with and without PCB-containing materials (reference apartments). We assessed exposure status by combining register-based information on relocation history with extrapolated values of exposure based on PCB-measurements in indoor air from subsets of the apartments. T2D cases were identified in the Danish registers during 1977–2018. We estimated adjusted hazard ratios (HR) and 95% confidence intervals (CI) using Cox regression analyses with time-varying exposure. ResultsWe identified 2737 incident T2D cases during the follow-up. Exposure to ≥3300 ng/m3 PCB × year (3rd tertile of PCByear) was associated with higher risk of T2D (HR 1.15, 95% CI 1.02–1.30) compared with exposure to <300 ng/m3 PCB × year (reference). However, among individuals with lower cumulated PCByear, the risk was similar to residents with exposure <300 ng/m3 PCB × year (300–899 ng/m3 PCB × year: HR 0.98, 95% CI 0.87–1.11; 900–3299 ng/m3 PCB × year: HR 0.96, 95% CI 0.83–1.10). DiscussionWe observed a marginally higher risk of T2D, but there was no evidence of an exposure-response relationship. The results should be interpreted with caution until confirmed in other independent studies of PCB exposure in indoor air.

Risk of cardiovascular diseases following residential exposure to airborne polychlorinated biphenyls: A register-based cohort study

BackgroundIndoor air in buildings constructed with materials containing polychlorinated biphenyls (PCBs) may be contaminated with especially lower-chlorinated PCBs. So far, the cardiovascular consequences of living with such contamination are unknown. ObjectivesTo determine the risk of cardiovascular disease (CVD) following residential exposure to predominantly lower-chlorinated PCBs in indoor air. MethodsThe Health Effects of PCBs in Indoor Air (HESPAIR) cohort is register-based with 51 921 residents of two residential areas near Copenhagen: Farum Midtpunkt and Brøndby Strand Parkerne. Here, indoor air was contaminated with PCB in one third of the apartments due to construction with materials containing PCB. Individual PCB exposure was estimated based on register-based information on relocation dates and indoor air PCB measurements in subsets of the apartments. Information on CVD was retrieved from the Danish National Patient Register for the follow-up period of 1977–2018. We estimated adjusted hazard ratios using Cox regression with time-varying exposure. ResultsCumulative residential exposure to airborne PCB was not associated with a higher overall risk for CVD (HR for highly exposed (≥3300 ng/m3 PCB × year): 1.02, 95% CI 0.94–1.10). This was also the case for most of the specific cardiovascular diseases, apart from acute myocardial infarction where a higher risk was observed for residents exposed to ≥3300 ng/m3 PCB × year compared to the reference group (HR 1.17, 95% CI 1.00–1.35). However, no exposure-response relationship was apparent and additional adjustment for education attenuated the risk estimate. DiscussionIn this, to our knowledge, first study ever to examine the risk of CVD following residential exposure to PCBs in indoor air, we observed limited support for cardiovascular effects of living in PCB-contaminated indoor air. Considering the prevalence of exposure to airborne PCBs and lack of literature on their potential health effects, these findings need to be corroborated in other studies.

Cancer Risk following Residential Exposure to Airborne Polychlorinated Biphenyls: A Danish Register-Based Cohort Study.

Background:Polychlorinated biphenyls (PCBs) are biopersistent chemicals classified as human carcinogens. This classification is primarily based on evidence on higher-chlorinated PCBs found in food. The carcinogenic potential of airborne lower-chlorinated PCBs remains largely unexplored.Objectives:We aimed to investigate cancer risk following residential exposure to airborne PCBs.Methods:Cancer risk was examined in the Health Effects of PCBs in Indoor Air (HESPAIR) cohort of 38,613 residents of two partly PCB-contaminated residential areas in Greater Copenhagen, identified by nationwide registries. PCB exposure was based on relocation dates and indoor air PCB measurements in subsets of apartments. Cancer diagnoses were extracted from the Danish Cancer Registry for the follow-up period of 1970–2018. We estimated adjusted hazard ratios with time-varying cumulative exposure and a 10-y lag using Cox regression.Results:Overall risk of cancer was not associated with , [hazard ratio (HR) for high-exposed vs. low-exposed ; 95% confidence interval (CI): 0.88, 1.09], but residents exposed to had higher risk of liver cancer (HR ; 95% CI: 1.28, 6.15) and meningiomas (HR ; 95% CI: 1.84, 6.64), with indications of exposure–response relationships. Results were suggestive of a higher risk of pancreatic cancer (HR ; 95% CI: 0.95, 2.64) at the highest aggregated PCB level. For testis cancer, a higher risk was observed among residents exposed to relative to residents exposed to (HR ; 95% CI: 1.41, 6.28), but the risk was not higher for residents exposed to . Apart from this, the risk of specific cancers was similar across exposure groups.Discussion:In this, to our knowledge, first population-based cohort study of residential exposure to airborne PCBs, we found no association between exposure to PCBs in indoor air in private homes and the risk for most of the specific cancers. Higher risk of liver cancer and meningiomas were observed. https://doi.org/10.1289/EHP10605

Residential exposure to airborne polychlorinated biphenyls and risk of cardiovascular diseases: A register-based cohort study

Background and aim Polychlorinated biphenyls (PCBs) are biopersistent chemicals ubiquitously present in our environment. Although exposure to lower-chlorinated PCBs (LC-PCBs) evaporating from building materials to indoor air is relatively common, the long-term cardiovascular effects remain unknown. We aimed to examine the risk of cardiovascular disease (CVD) following residential exposure to PCBs in indoor air. Methods The study builds on the register-based Health Effects of PCBs in Indoor Air (HESPAIR) cohort of 51,921 residents of two residential areas near Copenhagen: Farum Midtpunkt and Brøndby Strand Parkerne. Here, indoor air was contaminated with PCB in one third of the apartments. Indoor air measurements in subsets of apartments have documented large differences in PCB-concentrations between contaminated and uncontaminated apartments, dominated by LC-PCBs. Individual PCB-exposure was based on relocation dates from nation-wide registers and indoor air PCB-measurements and calculated as PCByear. CVD Information was retrieved from the Danish National Patient Register for the follow-up period 1977–2018. We estimated hazard ratios using Cox regression analyses with time-varying exposure adjusting for a priori identified potential confounders. Results Residential exposure to airborne PCB was not associated with a higher overall risk for CVD (HR for highly exposed: 1.02, 95% CI 0.95-1.11). The same was the case for most of the specific cardiovascular diseases apart from acute myocardial infarction where a 17% higher risk was observed for residents exposed to &amp;#x2265;3300 ng/m3*year compared to the reference group (HR 1.17, 95% CI 1.01-1.36). Conclusions In this first study to examine CVD risk following residential exposure to PCBs in indoor air, we observed only limited support for cardiovascular effects of living in PCB-contaminated air. Considering the prevalence of exposure to airborne PCBs and lack of knowledge on their potential health effects, these findings need to be corroborated in future studies. Key words lower-chlorinated PCBs; cardiovascular toxicity; environmental epidemiology; environmental pollutants

PCBs in indoor air and human blood in Pittsfield, Massachusetts

Concentrations of polychlorinated biphenyls (PCBs) and three chlorinated pesticides were determined in serum from 21 residents of Pittsfield, MA and in the basement, living room and outdoor air of the 10 homes in which they lived. Median serum PCB levels were 4.2 ng/g, which are at least four times the average level in the US population, and consisted primarily of more highly chlorinated, persistent congeners. This reflects contamination with PCBs coming from the local General Electric facility. Median basement air concentration was 20.3 ng/m3, while the median living room air was 11.4 ng/m3 and median outdoor air concentration was 3.0 ng/m3. The PCB congeners detected in air were primarily low chlorinated (four and fewer) congeners, reflecting the greater volatility of PCBs with fewer chlorines. The congener pattern between basement and living room air showed a 95% correlation, while correlation with outdoor air was much less. While the congener pattern in air is very different from that of the PCB products used in Pittsfield (Aroclors 1254 and 1260), low chlorinated PCBs are detected in the vapor phase after air is blown across the commercial mixtures. The human serum samples did not show detectible levels of many of the congeners seen in the basement air samples, reflecting rapid metabolism of lower chlorinated PCBs by the human body. However, with continuous inhalation of indoor air, especially in the living room, the exposure to these non-persistent congeners may still have adverse health effects. Cellular studies of some of these non-persistent, low chlorinated congeners indicate that they are neurotoxic, mutagenic and cytotoxic. These results demonstrate the importance of consideration of inhalation of PCBs as a route of exposure, especially in indoor sites, and suggest that monitoring serum PCB concentration may not always provide a good measurement of exposure, especially to congeners that are relatively rapidly metabolized but have significant toxicity.

PCB remediation in schools: a review.

Growing awareness of polychlorinated biphenyls (PCBs) in legacy caulk and other construction materials of schools has created a need for information on best practices to control human exposures and comply with applicable regulations. A concise review of approaches and techniques for management of building-related PCBs is the focus of this paper. Engineering and administrative controls that block pathways of PCB transport, dilute concentrations of PCBs in indoor air or other exposure media, or establish uses of building space that mitigate exposure can be effective initial responses to identification of PCBs in a building. Mitigation measures also provide time for school officials to plan a longer-term remediation strategy and to secure the necessary resources. These longer-term strategies typically involve removal of caulk or other primary sources of PCBs as well as nearby masonry or other materials contaminated with PCBs by the primary sources. The costs of managing PCB-containing building materials from assessment through ultimate disposal can be substantial. Optimizing the efficacy and cost-effectiveness of remediation programs requires aligning a thorough understanding of sources and exposure pathways with the most appropriate mitigation and abatement methods.

Evaluating health risks from inhaled polychlorinated biphenyls: research needs for addressing uncertainty.

Background: Indoor air concentrations of polychlorinated biphenyls (PCBs) in some buildings are one or more orders of magnitude higher than background levels. In response to this, efforts have been made to assess the potential health risk posed by inhaled PCBs. These efforts are hindered by uncertainties related to the characterization and assessment of source, exposure, and exposure-response.Objectives: We briefly describe some common sources of PCBs in indoor air and estimate the contribution of inhalation exposure to total PCB exposure for select age groups. Next, we identify critical areas of research needed to improve assessment of exposure and exposure response for inhaled PCBs.Discussion: Although the manufacture of PCBs was banned in the United States in 1979, many buildings constructed before then still contain potential sources of indoor air PCB contamination. In some indoor settings and for some age groups, inhalation may contribute more to total PCB exposure than any other route of exposure. PCB exposure has been associated with human health effects, but data specific to the inhalation route are scarce. To support exposure–response assessment, it is critical that future investigations of the health impacts of PCB inhalation carefully consider certain aspects of study design, including characterization of the PCB mixture present.Conclusions: In certain contexts, inhalation exposure to PCBs may contribute more to total PCB exposure than previously assumed. New epidemiological and toxicological studies addressing the potential health impacts of inhaled PCBs may be useful for quantifying exposure–response relationships and evaluating risks.Citation: Lehmann GM, Christensen K, Maddaloni M, Phillips LJ. 2015. Evaluating health risks from inhaled polychlorinated biphenyls: research needs for addressing uncertainty. Environ Health Perspect 123:109–113; http://dx.doi.org/10.1289/ehp.1408564

Mitigation of building-related polychlorinated biphenyls in indoor air of a school

BackgroundSealants and other building materials sold in the U.S. from 1958 - 1971 were commonly manufactured with polychlorinated biphenyls (PCBs) at percent quantities by weight. Volatilization of PCBs from construction materials has been reported to produce PCB levels in indoor air that exceed health protective guideline values. The discovery of PCBs in indoor air of schools can produce numerous complications including disruption of normal operations and potential risks to health. Understanding the dynamics of building-related PCBs in indoor air is needed to identify effective strategies for managing potential exposures and risks. This paper reports on the efficacy of selected engineering controls implemented to mitigate concentrations of PCBs in indoor air.MethodsThree interventions (ventilation, contact encapsulation, and physical barriers) were evaluated in an elementary school with PCB-containing caulk and elevated PCB concentrations in indoor air. Fluorescent light ballasts did not contain PCBs. Following implementation of the final intervention, measurements obtained over 14 months were used to assess the efficacy of the mitigation methods over time as well as temporal variability of PCBs in indoor air.ResultsControlling for air exchange rates and temperature, the interventions produced statistically significant (p < 0.05) reductions in concentrations of PCBs in indoor air of the school. The mitigation measures remained effective over the course of the entire follow-up period. After all interventions were implemented, PCB levels in indoor air were associated with indoor temperature. In a "broken-stick" regression model with a node at 20°C, temperature explained 79% of the variability of indoor PCB concentrations over time (p < 0.001).ConclusionsIncreasing outdoor air ventilation, encapsulating caulk, and constructing a physical barrier over the encapsulated material were shown to be effective at reducing exposure concentrations of PCBs in indoor air of a school and also preventing direct contact with PCB caulk. In-place management methods such as these avoid the disruption and higher costs of demolition, disposal and reconstruction required when PCB-containing building materials are removed from a school. Because of the influence of temperature on indoor air PCB levels, risk assessment results based on short-term measurements, e.g., a single day or season, may be erroneous and could lead to sub-optimal allocation of resources.

PCB-containing wood floor finish is a likely source of elevated PCBs in residents' blood, household air and dust: a case study of exposure

BackgroundPolychlorinated biphenyls (PCBs) are persistent pollutants identified worldwide as human blood and breast milk contaminants. Because they bioaccumulate, consumption of meat, fish, and dairy products predicts human blood concentrations. PCBs were also used widely in building materials, including caulks and paints, but few studies have evaluated the contribution of these exposures to body burden.MethodsIn an earlier study, we detected PCBs in indoor air in 31% of 120 homes on Cape Cod, MA. Two of the homes had much higher concentrations than the rest, so we retested to verify the initial finding, evaluate blood PCB concentrations of residents, and identify the PCB source.ResultsAir and dust concentrations remained elevated over 5 years between initial and follow-up sampling. Blood serum concentrations of PCBs in residents of the homes were generally elevated above the 95th percentile of a representative sample of the US population. Serum concentrations in residents and air and dust concentrations were especially high in a home where a resident reported use of PCB-containing floor finish in the past, and where the floor of one room was sanded and refinished just prior to sample collection.ConclusionThis case-study suggests that PCB residues in homes may be more significant contributors to overall exposure than diet for some people, and that use of a commercially-available PCB-containing wood floor finish in residences during the 1950s and 1960s is an overlooked but potentially important source of current PCB exposure in the general population.

Joint Sealants: An Overlooked Diffuse Source of Polychlorinated Biphenyls in Buildings

In October 2000, joint sealants containing polychlorinated biphenyls (PCB) were discovered in various public buildings in Switzerland. Triggered by this event, a nationwide comprehensive study was initiated by the Swiss Agency for the Environment, Forests, and Landscape, and 1348 samples of joint sealants as well as 160 indoor air samples from concrete buildings erected between 1950 and 1980 were analyzed. Out of 1348 samples, 646 (48%) contained PCB. In 279 (21%) samples, PCB concentrations of 10 g/kg and more were detected, and concentrations of 100 g/kg of PCB or more were found in 129 (9.6%) samples. These data indicate that PCB were widely used as plasticizers in joint sealants in Switzerland. In buildings constructed between 1966 and 1971, one-third of all joint sealants investigated contained more than 10 g/kg of PCB. PCB concentrations exceeding the limit of 0.050 g/kg above which material is required to be treated as PCB bulk product waste were reached by 568 samples (42%). PCB with a chlorine content between 45 and 55%, corresponding to mixtures such as Clophen A50, Aroclor 1248, and Aroclor 1254, were encountered in 316 samples (70%). In 42 cases (26%) where joint sealants containing PCB were present, clearly elevated PCB indoor air concentrations above 1 microg/m3 were encountered. In eight cases (5%), levels were higher than 3 microg/m3. The Swiss tentative guideline value of 6 microg/m3 (based on a daily exposure of 8 h) for PCB in indoor air was exceeded in one case (0.6%). On the basis of this work, representing the first large-scale nationwide analysis of the issue of PCB-contaminated joint sealants, we estimate that there are still 50-150 t of PCB present in these materials, acting as diffuse sources. They are distributed over many hundreds of buildings all over the country and represent a significant but frequently overlooked inventory of PCB. In light of the Stockholm Convention on persistent organic pollutants that entered into force last year, reduction of the release of PCB from these widely used materials is an important issue to be addressed.

Sampling and analysis of polychlorinated biphenyls in indoor air by sorbent enrichment followed by headspace solid-phase microextraction and gas chromatography–tandem mass spectrometry

In this study, a combination of solid-phase extraction (SPE) and solid-phase microextraction (SPME) techniques has been used to determine polychlorinated biphenyls (PCBs) in air. Using a vacuum pump, a known volume of air was pulled through a porous polymer (Tenax TA) where the target analytes were retained and then headspace SPME was carried out. The quantification was performed using gas chromatography coupled to tandem mass spectrometry. Certain factors, such as temperature and the addition of solvents to the adsorbent, were found to be very important for the transfer of the target PCBs from the Tenax to the SPME fiber. Some of these factors were studied using an experimental design strategy. Performance of the method was evaluated demonstrating that external calibration, which does not require performing the complete sampling process, was suitable. The coefficients of determination were calculated and a lack-of-fit test was run within the calibration data, demonstrating linearity of the method. Repeatability was found adequate (RSD ≤ 12%). Limits of detection (LODs) were found below 0.100 ng/m 3 when only 2.5 m 3 air were sampled. These LODs were low enough to check for harmful levels of PCBs in indoor air, and are well below the most restrictive limits established by countries regulations. In addition, more sensitivity could be attained by increasing the volume of air sampled (decrease in retention efficiency was not detected for sample volumes up to 25 m 3), and/or extending the extraction time in the SPME step.

Zehn Jahre PCB-Richtlinie - Versuch einer Bilanz aus hygienischer und umweltmedizinisch-toxikologischer Sicht

In 1995 a guideline was established in Germany, which requires the remediation of buildings with elevated indoor air concentrations of polychlorinated biphenyls (PCB). The action limit is 3000 ng/m(3). The tolerable PCB indoor air concentration is 300 ng/m(3). The aim of remediation actions is to reduce PCB in indoor air to levels < 300 ng/m(3) by removing the sources of PCB in buildings (mainly sealants, ceiling plates, wall colours). Based on this guideline a great number of school buildings, university buildings and administration buildings constructed in the 1960-ties and 1970-ties were renovated. In this paper, the toxicological basis of the aforementioned guide values are discussed. Furthermore, recent papers and proposals to establish lower guideline values for PCB in indoor air are discussed. The existing PCB guideline should be revised. When revising the guide values for PCB in indoor air it should be kept in mind that human PCB exposure is mainly via food, that PCB intake via food has been declining since more than 20 years, and that there is only a minor increase of PCB blood levels following inhalation of PCB in indoor air. In public discussions it should be clearly stated that remediation of PCB contaminated buildings is a preventive action. PCB concentrations in indoor air, which are associated with significant health risks, are presumably much higher than the current action value.

Evidence for increased internal exposure to lower chlorinated polychlorinated biphenyls (PCB) in pupils attending a contaminated school

External and internal exposure to six WHO-indicator congeners of polychlorinated biphenyls (PCB 28, 52, 101, 138, 153, 180) as well as subjective health complaints of a group of 377 pupils attending a PCB-contaminated school were compared with a control group of 218 pupils attending a non-contaminated school. Indoor air of the contaminated school revealed total PCB concentrations (sum of six indicator congeners times 5) ranging between 690 and 20,800 ng/m3 (median 2044 ng/m3). The lower chlorinated congeners PCB 28, 52, 101 were the prevailing contaminants (median 33, 293, and 66 ng/m3). Using improved analytical procedures at least one of the lower chlorinated congeners could be detected in 95% of the blood samples of pupils attending the contaminated school. Median concentrations for PCB 28, 52, 101, and for the sum of lower chlorinated congeners were 6, 9, 5, and 22 ng/l blood plasma, respectively, whereas the corresponding values in the control group were all < 1 ng/l. In contrast, no significant differences were found for the higher chlorinated congeners (PCB 138, 153, 180) which were detected in 1-2 orders of magnitude higher concentrations in both groups. Due to the dietary intake of these congeners similar total PCB levels were found (95th percentile 1070 and 1010 ng/l plasma in participants of the contaminated and control school). Using the Giessen Subjective Complaint List for Children and Adolescents no statistically significant differences in health complaints were observed between both groups of children. It is concluded that exposure of pupils to PCB in indoor air of the contaminated school caused increased blood concentrations of lower chlorinated congeners. Compared to background levels the detected excess body burden was very low indicating no additional health risk. Exposure was not associated to any specific subjective complaints.

Coplanar polychlorinated biphenyls (PCB) in indoor air.

Indoor air levels of coplanar polychlorinated biphenyls (mono- and non-ortho substituted PCB) of various buildings were determined. As a consequence of the presence of joint sealings containing PCB, total PCB concentrations in indoor air up to 4,200 ng/m3 were detected (data based on a survey including 29 sampling sites). In a PCB contaminated industrial building, total indoor air PCB levels up to 13,000 ng/m3 were measured. Typical PCB congeners in indoor air include PCB 28, PCB 52, and PCB 101. Concentrations of coplanar (dioxin-like) PCB have been determined for six different sites. The most abundant coplanar PCB congener in indoor air is PCB 118, followed by PCB 105, PCB 123, and PCB 77 in various order. Levels of coplanar PCB, expressed as toxicity equivalents (TEG), do correlate well with the total indoor air PCB concentration: a total PCB level of 1,000 ng/m3 corresponds to a concentration of coplanar PCB of 1.2 pg TEQ/m3. Based on this correlation and on an indoor air PCB level of 6,000 ng/m3 (tentative guideline value for PCB in indoor air in Switzerland based on a daily exposure of 8 h), the maximum daily intake of coplanar PCB via indoor air was estimated to be 0.6 pg TEQ/kg body weight.

Polychlorinated biphenyls in indoor air

Polychlorinated biphenyls in indoor air