Microplastics (MPs) and nanoplastics (NPs) released into drinking water from transmission pipes can pose a potential health risk to consumers. This paper presents the results of a comprehensive study of PE and PVC pipes after long-term operation in drinking water distribution networks, which confirmed that degradable polymers can be a significant source of MPs. Both plastics age relatively quickly, and the degree of damage to the pipe surface depends on the time and operating conditions. During aging, polymer chains deteriorate, leading to a weakening of the structure and increased amorphousness of the plastics. As a result, the surfaces of PE and PVC crack and peel, resulting in the formation of particles with sizes corresponding to NP and MP with high potential for release into water. The magnitude of the phenomenon increases as the diameter of the pipes decreases, indicating that the most vulnerable customers are those at the ends of the network to which drinking water is supplied through small-diameter pipes. Aging PE and PVC pipes should be considered a real and very important source of MPs and NPs in drinking water, and water quality in this aspect should be monitored by manufacturers.
Esophageal cancer (EC) is a malignancy with a poor prognosis and a five-year survival rate of less than 20%. It is the ninth most frequent cancer globally and the sixth leading cause of cancer-related deaths. The incidence of EC has been found to vary significantly by geography, indicating the importance of environmental and lifestyle factors along with genetic factors in the onset of the disease. In this work, we investigated mycotoxin exposure in a case-control study from the Arsi-Bale districts of Oromia regional state in Ethiopia, where there is a high incidence of EC while alcohol and tobacco use – two established risk factors for EC – are very rare.
Internal exposure to 39 mycotoxins and metabolites was assessed by liquid chromatography-tandem mass spectrometry in plasma samples of EC cases (n = 166) and location-matched healthy controls (n = 166) who shared similar dietary sources. Demographic and lifestyle data were collected using structured questionnaires. Principal Component Analysis and machine learning models were used to identify the most relevant demographic, lifestyle, and mycotoxin (co-)exposure variables associated with EC. Multivariate binary logistic regression analysis was used to assess EC risk.
Evidence of mycotoxin exposure was observed in all plasma samples, with 10 different mycotoxins being detected in samples from EC cases, while only 6 different mycotoxins were detected in samples from healthy controls. Ochratoxin A was detected in plasma from all cases and controls, while tenuazonic acid was detected in plasma of 145 (87.3%) cases and 71 (42.8%) controls. Using multivariable logistic regression analysis, exposure to tenuazonic acid (AOR = 1.88 [95% CI: 1.68–2.11]) and to multiple mycotoxins (AOR = 2.54 [95% CI: 2.10–3.07]) were positively associated with EC.
All cases and controls were exposed to at least one mycotoxin. Cases were exposed to a statistically significantly higher number of mycotoxins than controls. Exposure to tenuazonic acid and to multiple mycotoxins were associated with increased risk of EC in the study population. Although aflatoxin B1-lysine and the ratio of sphinganine to sphingosine (as a biomarker of effect to fumonisin exposure) were not assessed in this study, our result emphasizes the need to characterize the effect of mycotoxin co-exposure as part of the exposome and include it in risk assessment, since the current mycotoxin safety levels do not consider the additive or synergistic effects of mycotoxin co-exposure. Moreover, a prospective study design with regular sampling should be considered in this high incidence area of EC in Ethiopia to obtain conclusive results on the role of mycotoxin exposure in the onset and development of the disease.
Persistent organic pollutants (POPs) are stable compounds characterized by their resistance to degradation. From the 1960–70's organochlorine pesticides (OCPs), such as DDTs and polychlorinated biphenyls (PCBs) raised concerns regarding health and environmental impacts. This has led to the banning of POPs in the USA and Europe including Norway in 1980 and worldwide under the 2004 Stockholm Convention. The exposure of nursing infants to POPs has been a significant focus, prompting extensive research into the presence of these substances in human breast milk. In this study, we explored the temporal trends of POPs concentrations in breast milk sampled between 2002 and 2021 by comparing the concentration across the mother's year of birth.
Two Norwegian cohorts of lactating women were utilized (the HUMIS study and the “Iodine in Early Life”-Study). Concentrations of 15 different POPs, including PCBs, OCPs, and brominated diphenyl ethers (BDEs) were measured in 513 breast milk samples that had been collected over two decades in a subset of first-time mothers.
Time trend analysis indicated a steady decrease in concentration levels when adjusted for maternal age. The largest reduction was observed in β-HCH, age-adjusted (−17.1%, 95% CI -18.7, −15.4), followed by ∑6BDE (−9.1%, 95% CI -10.5, −7.7), ∑6PCBs (−7.1%, 95% CI -7.7, −6.5), and ∑2DDTs (−7.0%, 95% CI -8.0, −6.0). In contrast, an increasing trend was noted in the median concentrations of β-HCH, ∑2DDTs, and ∑6BDE in the mothers born in 1990–1994 to 1995–2002.
Our study demonstrates a decline of most POPs in breast milk, likely attributed to international regulatory efforts like the Stockholm Convention. Notably, an increase in the 95th percentile concentrations of β-HCH, ∑2DDTs, and ∑6BDEs was noted in mothers born in 1990–1994 compared to those born in 1995–2002 suggests demographic shifts that may influence exposure levels. Further research is needed to explore and understand the underlying factors for the rise in median concentrations of ∑6BDEs.
In a previous study located in Northeastern British Columbia (Canada), we observed associations between density and proximity of oil and gas wells and indoor air concentrations of certain volatile organic compounds (VOCs). Whether conventional or unconventional well types and phases of unconventional development contribute to these associations remains unknown.
To investigate the associations between proximity-based metrics for conventional and unconventional wells and measured indoor air VOC concentrations in the Exposures in the Peace River Valley (EXPERIVA) study samples.
Eighty-four pregnant individuals participated in EXPERIVA. Passive indoor air samplers were analyzed for 47 VOCs. Oil and gas well legacy data were sourced from the British Columbia Energy Regulator. For each participant's home, 5 km, 10 km and no buffer distances were delineated, then density and Inverse Distance Square Weighted (ID2W) metrics were calculated to estimate exposure to conventional and unconventional wells during pregnancy and the VOC measurement period. Multiple linear regression models were used to test for associations between the well exposure metrics and indoor air VOCs. For exposure metrics with >30% participants having a value of 0, we dichotomized exposure (0 vs. >0) and performed ANOVAs to assess differences in mean VOCs concentrations.
Analyses indicated that: 1) conventional well density and ID2W metrics were positively associated with indoor air acetone and decanal; 2) unconventional well density and ID2W metrics were positively associated with indoor air chloroform and decamethylcyclopentasiloxane, and negatively associated with decanal; 3) drilling specific ID2W metrics for unconventional wells were positively associated with indoor air chloroform.
Our analysis revealed that the association between the exposure metrics and indoor air acetone could be attributed to conventional wells and the association between exposure metrics and indoor air chloroform and decamethylcyclopentasiloxane could be attributed to unconventional wells.
Environmental pollution is of global concern. In Southeast Sweden, historical glass production has contaminated communities with toxic metals. Long-term residency in these communities and high consumption of local foods may constitute a risk for cardiovascular disease (CVD) or stroke.
The current study investigates if residency in these contaminated sites and long-term consumption of local foods is associated with self-reported CVD and stroke. In addition, the body burden of the toxic metals arsenic, cadmium, and lead, as well as inflammatory protein markers, were studied for association with CVD and stroke.
From an existing questionnaire cohort and biomonitoring sub cohort (n = 2290/882) of people living in the contaminated areas, self-reported CVD cases (n = 366/166) and stroke cases (n = 78/25) were identified. Individuals were grouped based on their residency within a 2 km radius of glassworks with historical high, moderate, or low air-borne lead emissions. Body burden of arsenic, cadmium, and lead was analyzed using ICP-MS. Inflammatory markers were investigated using electrochemiluminescence.
Long-term residency near glassworks with historically high levels of lead emissions, and high consumption of local foods, were associated with CVD. The risk was increasing for each year of residency in high emission areas. Increased body burden of arsenic in blood, and lead in urine, were associated with stroke. Five and two inflammatory markers, respectively, were elevated in CVD and stroke cases after adjusting for confounders.
An increased risk for CVD was found in areas with historically high emissions of lead but possibly also other toxic metals. Interestingly, there was an indication of a dose-response relationship with increasing risk for CVD per year of residency time. Inhalation and consumption of local food may constitute major pathways for this association. The study shows that long-term exposure to toxic metals in these contaminated areas is associated with CVD and that there is a need to limit exposure in the general population.
During the storage and distribution of water in buildings, the excessive growth of pathogens can deteriorate the quality of drinking water. This study aims to investigate the factors influencing this growth and propose technical measures for prevention. The analysis is based on an empirical data set comprising 1361 samples from 204 domestic premise plumbing systems. In 14 systems, ultrafiltration plants were installed as microbiological barriers. Legionella cultivation and flow cytometry were used to determine microbiological properties. The study identified elevated total cell counts in tapping valves and pipe end lines in numerous premise plumbing systems, indicating prolonged water stagnation prior to sampling, which facilitates microbiological growth. Higher contamination rates were observed in these systems, with peripheral taps often being contaminated in lieu of the entire system. These systems were classified as microbiologically unstable due to the relevantly higher total cell numbers at hot water taps compared to the hot water tank (>25%). Furthermore, these systems exhibited a Legionella contamination rate that was 22.3% higher than in microbiologically stable systems. In some cases, peripheral contaminations may not accurately represent the entire premise plumbing system. Increasing the discard volume during sampling from 1 L to 3–5 L could provide more precise results during standard testing. Legionella species were primarily detected in the first 1 L of water after tap activation. Additionally, statistically significant relationships were observed between direct temperature and total cell number, as well as between the presence of ultrafiltration and total cell numbers at cold water taps.
There is growing interest in cardiometabolic outcomes associated with nighttime noise, given that noise can disturb sleep and sleep disturbance can increase cardiometabolic risk such as hypertension. However, there is little empirical research evaluating the association between nighttime aircraft noise and hypertension risk. In this study, we expand on previous work to evaluate associations between nighttime aircraft noise exposure and self-reported hypertension incidence in the Nurses' Health Studies (NHS/NHSII), two US-wide cohorts of female nurses. Annual nighttime average aircraft sound levels (Lnight) surrounding 90 airports for 1995–2015 (in 5-year intervals) were modeled using the Aviation Environmental Design Tool and assigned to participants’ geocoded addresses over time. Hypertension risk was estimated for each cohort using time-varying Cox proportional-hazards models for Lnight dichotomized at 45 dB (dB), adjusting for individual-level hypertension risk factors, area-level socioeconomic status, region, and air pollution. Random effects meta-analysis was used to combine cohort results. Among 63,229 NHS and 98,880 NHSII participants free of hypertension at study baseline (1994/1995), we observed 33,190 and 28,255 new hypertension cases by 2014/2013, respectively. Although ∼1% of participants were exposed to Lnight ≥45 dB, we observed an adjusted hazard ratio (HR) of 1.10 (95% CI: 0.96, 1.27) in NHS and adjusted HR of 1.12 (95% CI: 0.98, 1.28) in NHSII, comparing exposure to Lnight ≥45 versus <45 dB(A). In meta-analysis, we observed an adjusted HR of 1.11 (95% CI: 1.01, 1.23). These results were attenuated with adjustment for additional variables such as body mass index. Our findings support a modest positive association between nighttime aircraft noise and hypertension risk across NHS/NHSII, which may reinforce the concept that sleep disturbance contributes to noise-related disease burden.
Perfluoroalkyl and polyfluoroalkyl substances (PFAS) have demonstrated potential toxicity in skeletal development. However, the relationship between prenatal PFAS exposure and offspring bone health remains unclear in epidemiological studies. Therefore, we aim to investigate whether prenatal exposure to PFAS is associated with bone mineral density (BMD) in offspring.
This study population included 182 mother-child pairs in the Shanghai Obesity and Allergy Cohort, enrolled during 2012–2013. 10 PFAS were measured by liquid chromatography-mass spectrometry (LC-MS) in cord plasma. The child's spinal BMD was measured using a dual-energy X-ray absorptiometry (DXA) scanner at the age of 8. Multivariable linear regression models were used to estimate the associations between individual PFAS concentrations (as a continuous variable or categorized into quartiles) and child BMD. Bayesian kernel machine regression (BKMR) was employed to explore the joint effects of PFAS mixtures on BMD.
Among the 10 PFAS, 8 of them had a detection rate >90% and were included in the subsequent analysis. We observed no significant associations between individual PFAS (as a continuous variable) and spinal BMD in 8-year-old children using the multivariable linear regression model. When treated as quartile categories, the second and fourth quartiles of perfluorobutane sulfonate (PFBS) was associated with higher BMD in the first lumbar vertebra, compared with the lowest quartile. BKMR analysis revealed no association between the PFAS mixture and child BMD.
We observed no associations of prenatal PFAS exposure with child BMD at 8 years of age. Given the inconsistent epidemiological evidence, further research is needed to confirm these findings from other studies or elucidate the potentially toxic effects of PFAS on bone.
Water, sanitation and hygiene (WASH) associated diseases remain a global public health issue and linked with Sustainable Development Goal 6. In November 2020, a war broke out in Tigray, Ethiopia, resulting in a negative health consequence. The post war status of WASH and its associated diseases are not documented. The aim of this study was to assess the status of drinking water, sanitation and hygiene practices and the prevalence of WASH-associated diseases in Tigray, Ethiopia following the war. A community-based cross-sectional study was conducted in 24 randomly selected accessible districts of Tigray, Ethiopia. A standardized questionnaire was used to collect data from households in the study. Data was collected from 2338 households. Descriptive statistics and binary logistic regression were used to analyze the data. The average age of respondents was 28.7 years (SD = 6.2). The majority of respondents 2030 (86.8%) were married and 1698 (72.6%) were rural residents. Nearly one third of the respondents were uneducated and around 40% have either radio or TV as means of communication. More than half (55.2%) of the respondents had a family size of over 5.
A quarter (25%, 95% CI: 23.3, 26.8) of study participants had access to a basic water supply. Less than a tenth (7.7%, 95% CI: 6.6, 8.8) of households had access to basic sanitation. Basic hand washing was available in 2% of households. Malaria, diarrhoea, skin infection and eye infection were the common reported disease in the community. Marital status, family size, place of residence and liquid waste management were the most important predictors of reported diseases.
Access to basic water, sanitation and hygiene services was low, and the prevalence of malaria, diarrhoea and skin infections was higher. There were differences in WASH services and reported diseases according to zone and place of residence (urban-rural). Post war, improved access to basic water, sanitation and hygiene services is recommended to prevent WASH-associated diseases in Tigray, Ethiopia. Furthermore, the prevention oriented policy of the country needs better implementation to reduce preventable diseases and ensure better health status in the community.