Estimated daily intake and hazard quotients and indices of phthtalate diesters for young danish men

Urinary excretion of phthalates and the substitutes DINCH and DEHTP in Danish young men and German young adults between 2000 and 2017 - A time trend analysis

Over the last twenty-five years it has become evident that exposure to several phthalates can have adverse effects on human health, such as endocrine disruption. This led to a series of EU regulations that resulted in a decrease in the production volumes of the restricted phthalates and an increased production of substitutes. The current study describes the impact of regulations and changes in production and use of phthalates and their substitutes on internal exposure patterns in two European populations since the beginning of the 2000'ies. Using harmonised data from young adults in Denmark (Danish Young Men Study, n = 1,063, spot urine) and Germany (Environmental Specimen Bank, n = 878, 24-h urine) with repeated cross-sectional design (3-11 cycles per biomarker) we applied Locally Estimated Scatterplot Smoothing (LOESS) and Generalized Linear Models (GLMs) to estimate time trends and the role of covariates on the trend (e.g. age, BMI). Time trends of daily excretion (μg/24h) are comparable between the two samples for the regulated (DEHP, BBzP, DiNP, DnBP, DiBP, DiDP/DPHP) as well as the non-regulated substances (DMP, DEP, DINCH, DEHTP) although the rate of change differ for some of the compounds. GLM results indicate that the daily excretion of the most regulated phthalates has decreased over time (DEHP yearly about 12-16%, BBzP 5%, DnBP 0.3-17%, and DiBP 4-12%). Interestingly, also the non-regulated phthalates DMP and DEP decreased by 6-18% per year. In sharp contrast, the phthalate substitutes DINCH and DEHTP show very steep annual increases (∼10-68% and ∼100%, respectively) between 2009 and 2017. We did not find an effect of age, sex, BMI, or education on the time trend. The present study provides comparable insights into how exposure to phthalates and two of their substitutes have changed over the last two decades in Germany and Denmark.

Effect of plastic film mulching and film residues on phthalate esters concentrations in soil and plants, and its risk assessment

The application of plastic film mulching can greatly improve dryland productivity, while the release of toxic phthalate esters (PAEs) from the plastic film has generated concern. This study investigated the effects of mulched plastic film and residual plastic film on the PAE concentrations in the soil-crop system and assessed the risks to people eating crop products. The PAEs concentration in the 0-25 cm soil layer of plastic mulched farmland was 0.45-0.81 mg/kg, while the average PAEs concentration of 0.37-0.73 mg/kg in non-mulched farmland decreased by 19%. The PAEs concentration in mulched soil reached the highest in July, being 0.80-0.84 mg/kg, while in the non-mulched soil, the PAEs also appeared and gradually decreased from May at 0.62-0.74 mg/kg to October, and the PAEs concentrations were almost the same in the mulched and non-mulched soils at the harvest time in October at 0.37-0.44 mg/kg. With the amounts of residual film in farmland increasing from 0 kg/ha to 2700 kg/ha (equivalent to the total amount of residual film after 60 years of continuous plastic film mulching), the PAEs concentrations were no significant changes, being 0.54-0.93 mg/kg. Maize (Zea mays L.) roots could absorb and accumulate PAEs, and the bio-concentration factor (BCF) was 1.6-2.3, and the average PAEs concentrations in stems, leaves, and grains were 79%-80% of those in roots at 0.77-1.47 mg/kg. For the ingestion of maize grains or potato (Solanum tuberosum L.) tubers grown in plastic film mulched farmland or farmland containing residual film of 450-2700 kg/ha, the hazard index (HI) were less than 1, the carcinogenic risks (CRs) were 2.5 × 10^-7-2.2 × 10^-6, and the estrogenic equivalences were 6.17-17.73 ng E₂/kg. This study provides important data for the risk management of PAEs in farmlands.

Reduction effects of solar radiation, mechanical tension, and soil burial on phthalate esters concentrations in plastic film and soils

Phthalate esters (PAEs) are potentially dangerous chemicals in plastic film mulched fields; however, few studies have investigated how to reduce their concentrations in plastic film and soil. In this study, the effects of solar radiation, mechanical tension, and soil burial on PAEs concentrations in polyethylene (PE) film and degradable film were investigated, and the half-lives of di-n-butyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) in soil also studied. PAEs concentrations in polyethylene films were about twice those in the degradable films; however, PAEs concentrations in all experimental films were similar after 1-year of field exposure. Mechanical tension had no effect on the PAEs concentrations of polyethylene films, but increased the detected concentrations of PAEs in degradable films by 34%-120%. After 4-years of burial, the PAEs concentrations in films decreased by 79.2%-98.0%, and mechanical tension promoted the reductions. However, there was little difference in PAEs concentrations between the buried soils with and without films, indicating the released PAEs reduced quickly in soil. Also, the half-lives of DBP and DEHP were 2.4-4.6 days and 18.5-41.4 days, respectively. Overall, the results presented herein provide reasonable approaches to reduce the concentrations of PAEs in plastic films and soils.

A critical review on human internal exposure of phthalate metabolites and the associated health risks

Phthalates (PAEs) are popular synthetic chemicals used as plasticizers and solvents for various products, such as polyvinyl chloride or personal care products. Human exposure to PAEs is associated with various diseases, resulting in PAE biomonitoring in humans. Inhalation, dietary ingestion, and dermal absorption are the major human exposure routes. However, estimating the actual exposure dose of PAEs via an external route is difficult. As a result, estimation by internal exposure has become the popular analytical methods to determine the concentrations of phthalate metabolites (mPAEs) in human matrices (such as urine, serum, breast milk, hair, and nails). The various exposure sources and patterns result in different composition profiles of PAEs in biomatrices, which vary from country to country. Nevertheless, the mPAEs of diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), di-iso-butyl phthalate (DiBP), and di-(2-ethylhexyl) phthalate (DEHP) are predominant in the urine. These mPAEs have greater potential health risks for humans. Children have been observed to exhibit higher exposure risks to several mPAEs than adults. Besides age, other influencing factors for phthalate exposure are gender, jobs, and residential areas. Although many studies have reported biological monitoring of PAEs, only a few reviews that adequately summarized the reports are available. The current review appraised available studies on mPAE quantitation in human biomatrices and estimated the dose and health risks of phthalate exposure. While some countries lack biomonitoring data, some countries' data do not reflect the current PAE exposure. Thence, future studies should involve frequent PAE biomonitoring to accurately estimate human exposure to PAEs, which will contribute to health risk assessments of human exposure to PAEs. Such would aid the formulation of corresponding regulations and restrictions by the government.

Time course of phthalate cumulative risks to male developmental health over a 27-year period: Biomonitoring samples of the German Environmental Specimen Bank

In several human biomonitoring surveys, changes in the usage patterns of phthalates have come to light, but their influence on the risks associated with combined exposures is insufficiently understood. Based on the largest study to date, the 27-year survey of urinary phthalate metabolite levels in 24-hour urine samples from the German Environmental Specimen Bank, we present a deep analysis of changing phthalate exposures on mixture risks. This analysis adopts the Hazard Index (HI) approach based on the five phthalates DBP, DIBP, BBP, DEHP and DINP. Calculations of the hazard index for each study participant included updated phthalate reference doses for anti-androgenicity (RfD_AAs) that take account of new evidence of phthalates' developmental toxicity. The Maximum Cumulative Ratio (MCR) approach was used to establish whether a subject's combined exposure was dominated by one phthalate or was influenced by several phthalates simultaneously. Generally, over the years there was a shift towards lower HIs and higher MCRs, reflecting an increased complexity of the combined exposures. The decade from 1988 to about 1999 was characterised by rather high HIs of between 3 and 7 (95th percentile) which were driven by exposure to DBP and DEHP, often exceeding their single acceptable exposures. Traditional single phthalate risk assessments would have underestimated these risks by up to 50%. From 2006 onwards, no study participant experienced exposures above acceptable levels for a single phthalate, but combined exposures were still in excess of HI = 1. From 2011 onwards most individuals stayed below HI = 1. In interpreting these results, we caution against the use of HI = 1 as an acceptable limit and develop proposals for improved and more realistic mixture risk assessments that take account of co-exposures to other anti-androgenic substances also capable of disrupting the male reproductive system. From this perspective, we regard HIs between 0.1 and 0.2 as more appropriate for evaluating combined phthalate exposures. Assessed against lowered HIs of 0.1 - 0.2, the combined phthalate exposures of most study participants exceeded acceptable levels in all study years, including 2015. Continued monitoring efforts for phthalate combinations are required to provide the basis for appropriate risk management measures.

Which chemicals should be grouped together for mixture risk assessments of male reproductive disorders?

There is concern about cumulative exposures to compounds that disrupt male sexual differentiation in foetal life, leading to irreversible effects in adulthood, including declines in semen quality, testes non-descent, malformations of the penis and testis cancer. Traditional chemical-by-chemical risk assessment approaches cannot capture the likely cumulative health risks. Past efforts of focusing on combinations of phthalates, a subgroup of chemicals suspected of contributing to these risks, do not go far enough, as they ignore the contribution of other types of chemicals. With the aim of providing criteria for the inclusion of additional chemicals in mixture risks assessments for male reproductive health, this paper examines the mechanisms of action of various chemicals capable of disrupting male sexual differentiation. An Adverse Outcome Pathway (AOP) network for malformations of the male reproductive system is constructed that includes new findings about the role of disruptions of prostaglandin signalling. This network is used to identify pathways that converge at critical nodal points to produce down-stream adverse effects. From this knowledge, combinations of chemicals with different mechanisms of action are predicted that should result in cumulative effects. These predictions are then mapped against evidence from experimental mixture studies with relevant combinations. From the outcome of this analysis it is concluded that cumulative assessment groups for male reproductive health risks should not only include phthalates but also comprise androgen receptor (AR) antagonists, chemicals capable of disrupting steroid synthesis, InsL3 production, prostaglandin signalling and co-planar polychlorinated dibenzo-dioxins together with other dioxin-like compounds. This list goes far beyond what has been suggested previously. A minimum set of chemicals to be assessed together with phthalates includes pesticides such as vinclozolin, prochloraz, procymidone, linuron, the pain killers paracetamol, aspirin and ibuprofen, pharmaceuticals such as finasteride, ketoconazole, and the lipid-lowering drug simvastin, poly-chlorinated dibenzo-dioxins and other dioxin-like pollutants and phenolics such as bisphenol A and butylparaben. AOP network analyses are essential to overcome difficulties in establishing groupings of chemicals for mixture risk assessments that derive from a narrow focus on mechanisms and modes of action.

Di-(2-ethylhexyl) phthalate (DEHP)-induced hepatotoxicity in quail (Coturnix japonica) via suppression of the heat shock response

Di-(2-ethylhexyl) phthalate (DEHP) is a widespread environmental toxicant that severely impacts agricultural production and animal and human health. Nevertheless, DEHP-induced hepatotoxicity at the molecular level in quail remains unexplored. The heat shock response (HSR), involving heat shock proteins (HSPs) and heat shock transcription factors (HSFs), is a highly conserved molecular response that is triggered by stressors, especially exposure to toxicants. To explore the DEHP-induced hepatotoxicity that occurs via regulation of HSR in birds, female quail were dosed with DEHP by oral gavage (0, 250, 500 and 1000 mg/kg) for 45 days. Based on histopathological analysis, the livers of the DEHP-treated groups exhibited structural alterations of hepatocytes, including mitochondrial swelling, derangement of hepatic plates, inflammatory cell infiltration and adipose degeneration. Ultrastructural evaluation of the livers of DEHP-treated quail revealed swollen mitochondria, partial disappearance of mitochondrial membranes and cristae, nuclear chromatin margination and nuclear condensation. The expression of HSF1 and HSF3 significantly decreased after DEHP exposure. The levels of HSPs (HSP10, HSP25, HSP27, HSP40, HSP47, HSP60, HSP70 and HSP90) were significantly downregulated in the livers of DEHP-treated quail. In this study, we concluded that DEHP exposure resulted in liver function damage and hepatotoxicity by reducing the expression of HSFs and HSPs in quail liver, which inhibited the protective effect of the HSR signaling pathway.

Estimating population exposure to phthalate esters in major Chinese cities through wastewater-based epidemiology

Phthalate esters (PAEs) are widely used in consumer and industrial products and may thus pose significant health risks. Urine analysis, which has usually been applied to assess the health risks of PAEs, has the drawback of small sample sizes and insufficient representativeness. Wastewater-based epidemiology (WBE) collects wastewater samples containing urine from the entire community and thus is more representative than urine samples. In this work, exposure levels and health risks of PAEs were estimated on a national scale for the first time through the WBE approach. Wastewater samples were collected from 54 wastewater treatment plants in 27 major cities that cover all of the geographic regions of China. The estimated ∑5PAEs exposure levels ranged from 290 μg/inh/d (Lhasa) to 3642 ± 467 μg/inh/d (Zhengzhou) with a mean level of 2184 ± 1173 μg/inh/d. Di-n-butyl phthalate accounted for the highest proportion (65%) in the total exposure level. The ∑5PAEs exposure levels in Southwest China were significantly lower than those in other regions due to the low production and consumption of plastics in the region. The health risks of PAEs were assessed by comparing the estimated daily exposure levels to the acceptable daily exposure levels. For adults, the hazard index that represents cumulative risk of PAEs was above or below 1 depending on a particular reference dose (total daily intake values or the reference dose for anti-androgenicity) that was used for risk calculation. In contrast, the hazard index was above 1 for a significant number of cities for children, regardless of which reference dose was used. The results indicate that health risks of PAE exposure in China cannot be overlooked. Children in China are under considerably greater risks than adults, which warrants further research or proper regulation of PAE use in China.

The concentrations and cumulative risk assessment of phthalates in general population from Shanghai: The comparison between groups with different ages

Phthalates are predominantly used as plasticizers in daily consumer products. People are regularly exposed to phthalates through contact with these products. Phthalates are suspected to cause adverse effects in general population. We detected 10 metabolites of 6 phthalates in 3348 urine samples of general population (infants (0-1 yr), children and adolescents (2-19 yr), adults (≥20 yr), and pregnant women) from Shanghai. The Daily intake for phthalates was estimated based on the levels of urinary metabolites. Hazard quotient (HQ) was used to evaluate the risk from the exposure to a single chemical. For the cumulative risk calculation, HQs of different phthalates were added to produce the Hazard index (HI). Overall, exposure was low in adults but presented at a relatively high level throughout childhood. The exposure to some specific phthalates was high in infants and pregnant women. The cumulative risk assessment showed cause for concern mainly for infants and children subgroups. The results indicated that general population from Shanghai was widely exposed to phthalates and the infants were possibly at a high risk of cumulative exposure to phthalates.

Variation in accumulation, transport, and distribution of phthalic acid esters (PAEs) in soil columns grown with low- and high-PAE accumulating rice cultivars

The extensive use of plasticizers containing di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) results in high residual concentrations in agricultural soils and poses potential risks to human health through the food chain. Here, two rice cultivars with low (Fengyousimiao) and high (Peizataifeng) phthalic acid ester (PAE) accumulation were grown in leaching columns packed with DBP- and DEHP-contaminated soils to investigate their transport, fraction distribution, and accumulation in soil-rice-water system. Significant differences in soil vertical distribution of DBP and DEHP were observed among the two cultivars, sterilization and non-sterilization treatments. Both DBP and DEHP could leach to the bottom layer even though their concentrations in both soil and pore water decreased along with soil depth. DBP and DEHP concentrations in pore water were significantly correlated with those in corresponding soil layer at ripening stage. The available fractions including desorbing and non-desorbing fractions were predominant in the total concentrations of DBP and DEHP of soils. DBP and DEHP storages in coarse soil fractions (i.e., coarse and fine sands) with higher bioavailability displayed higher bioconcentration factors compared to finer soil fractions (i.e., silt and clay), and bioconcentration factors of Peizataifeng were higher than those of Fengyousimiao. The variations in vertical migration and accumulation of DBP and DEHP by the two cultivars implied different adverse effects on the security of groundwater and food.

Aggregating exposures & cumulating risk for semivolatile organic compounds: A review

Increasingly, health risk assessment is addressing multiple pathway exposures to multiple contaminants. We reviewed aggregated exposure and cumulative risk approaches for contemporary and ubiquitous semivolatile organic compounds (SVOC). We identified 22 studies aggregating exposure pathways, and 31 cumulating risk. Exposure aggregation is based on the addition of pathway-specific doses, using kinetic modeling where it exists, and classic external dose equations otherwise. In most cases, exposure is dominated by a single route or source of exposure - mainly the oral pathway - via dietary or non-dietary exposure. Preferential routes and sources of exposure are influenced by SVOC physical-chemical properties such as vapor pressure. The cumulative risk approach for contaminants is based on dose addition. Simple sum of hazard quotient (Hazard Index: HI) is the most commonly used cumulative risk assessment approach, while Relative Potency Factor (RPF) appeared to the best suited - although this calls for a level of toxicological information that limits the number of compounds that can be studied simultaneously. Where both were performed, moving from HI to more refined approach produced similar results. In conclusion, both approaches - exposure aggregation and cumulative risk - rely on simple assumptions. Nevertheless, they allow uncertainty to be reduced, in comparison with source-by-source or chemical-by-chemical approaches.

Estimated Daily Intake and Cumulative Risk Assessment of Phthalates in the General Taiwanese after the 2011 DEHP Food Scandal

A food scandal occurred in Taiwan in 2011 because the DEHP (di-2-ethylhexyl phthalate) had been intentionally used in food products. We assessed the daily intakes (DIs) and cumulative risk of phthalates in Taiwan’s general population after the scandal. The DIs of 6 phthalates, including di-n-butyl phthalate (DnBP), di-iso-butyl phthalate (DiBP), and DEHP, were evaluated using urinary phthalate metabolites. Hazard quotients of phthalates classified as affecting the reproductive (HQ_rep) and hepatic (HQ_hep) systems were assessed using cumulative approach. The creatinine-based model showed that the highest DI values in children 7-to 12- years-old were for DEHP (males: median: 4.79 μg/kg bw/d; females: median: 2.62 μg/kg bw/d). The 95^th percentile (P95) of HQ_rep values were all >1 in the 7- to 12-year-old and 18- to 40-year-old male groups. The P95 of HQ_hep values were all >1 in the 7- to 18- year-old male groups. Most of the HQ_rep was attributable to the HQs of DnBP and DiBP (53.9–84.7%), and DEHP contributed most to HQ_hep (83.1–98.6%), which reveals that DnBP, DiBP and DEHP were the main risk of phthalate exposure for Taiwanese. Taiwan’s general population is widely exposed to DnBP, DiBP and DEHP, especially for young children.

Variation in accumulation and translocation of di-n-butyl phthalate (DBP) among rice (Oryza sativa L.) genotypes and selection of cultivars for low DBP exposure

Di-n-butyl phthalate (DBP) is a typical endocrine-disrupting chemical with higher detection frequency and concentration in agricultural soil (particularly in paddy-field soil of Guangdong Province) of China. In this study, a greenhouse experiment was conducted to investigate variation in uptake and accumulation of DBP by 20 rice cultivars and to screen low DBP-accumulating cultivars. DBP concentrations in plants varied greatly with rice cultivars, growth stages, and tissues. The highest DBP concentrations in both roots and shoots were observed at the ripening stage, with concentrations 2-100-fold higher than those at tillering, jointing, and flowering stages. At the ripening stage, DBP concentrations decreased in the order of leaf > root > stem > grain, and significant differences of DBP concentrations were observed among various rice cultivars. Moreover, the magnitude of variation in DBP concentrations among various cultivars was greater in stems and grains than in roots and leaves. The translocation factors of DBP from roots to stems and from shoots to grains were <1.0, and those from stems to leaves were almost >1.0. Overall, cultivars Yuxiangyouzhan, Jinnongsimiao, Tianyou 122, and Wuyou 380 accumulated relatively lower DBP in grains, resulting in lower DBP exposure. The DBP uptake and translocation pathways in rice require further investigation. Graphical abstract ᅟ.

Sorption and degradation of phthalate esters by a novel functional hyper-cross-linked polymer

A novel functional hyper-cross-linked polymer (NFHP) modified with trimethylamine was prepared. NFHP was characterized by FTIR, XPS, XRD, SEM and Micromeritics ASAP-2010 automatic surface area analysis instrument. Adsorption and hydrolysis degradation of phthalate acid esters (PAEs) by NFHP were also investigated as a function of temperature, equilibrium concentration and PAEs types. Results indicated that NFHP could adsorb and catalyze hydrolysis of PAEs simultaneously. There was a positive relationship between the removal capacity and temperature, equilibrium concentration, and PAEs hydrophobicity. However, the increase of PAEs equilibrium concentration and hydrophobicity resulted in the decreased level of their hydrolysis, while high temperature promoted the hydrolysis of PAEs. Film diffusion was the rate controlling step of the removal process. The apparent removal rate of PAEs increased as temperature increased due to the higher diffusion coefficient at higher temperature. The results of continuous fixed-bed runs demonstrated that NFHP was capable of synchronously removing PAEs and their hydrolysis products from tap water. In the effluent solution, the PAEs concentration was below the detection limit (0.01 mg/L) of HPLC within 1400 BVs. Moreover, the exhausted NFHP beads can be completely regenerated for repeated use. Physical adsorption, hydrolysis degradation and ion-exchange played significant roles in removing of PAEs and their hydrolysis products. The analysis of hydrolysis products, FTIR and XPS spectra proved that physical adsorption, hydrolysis and ion-exchange were the main removal mechanism. The results reported herein suggested that this novel material has a great potential in efficient removal of PAEs from wastewater.

Temporal variability of urinary concentrations of phthalate metabolites, parabens and benzophenone-3 in a Belgian adult population

In the present study, we investigated the temporal within-person variability of the exposure biomarker for phthalates, parabens and benzophenone-3 (BP3) in 32 Belgian adults, each providing 11 urine spots during 4 months. We calculated the intraclass coefficient correlation (ICC), the sensitivity and the specificity to assess the temporal reproducibility and to investigate the predictive ability of the spot measurements for these classes of chemicals. Additionally, we explored the temporal variability of the estimation of the cumulative risk of exposure to phthalates (hazard index; HI). We observed fair ICC ranging from 0.55 to 0.68 for parabens, monoethyl phthalate (MEP), mono-iso-butyl phthalate (MiBP) and BP3, but lower ICC, from 0.20 to 0.49, for monobenzyl phthalate (MBzP), mono-n-butyl phthalate (MnBP), mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-oxo-hexyl phthalate (5-oxo-MEHP) and mono-2-ethyl-5-hydroxy-hexyl phthalate (5-OH-MEHP). The ICC estimated for HI (0.49) reflected a moderate reproducibility. The measurements in spot samples were moderate to good predictor of the 4-month level of exposure for parabens, MEP, MnBP, MiBP, BP3 and HI (sensitivity ranging from 0.67 to 0.77), but lower predictor for MEHP, 5-oxo-MEHP, 5-OH-MEHP and MBzP (sensitivity ranging from 0.58 to 0.63). The sensitivity could be increased when several spot urinary levels were averaged to predict the long-term level of exposure. Globally, our results indicate that a single spot measurement seems to correctly represent the long-term exposure for parabens, BP3, MEP, MiBP and HI. Additional spot samples seemed to be needed for the proper exposure assessment of the other target compounds.

Genotypic variation in the uptake, accumulation, and translocation of di-(2-ethylhexyl) phthalate by twenty cultivars of rice (Oryza sativa L.)

Agricultural soil in China contains high levels of di-(2-ethylhexyl) phthalate (DEHP), especially in paddy-field soil of Guangdong province of China, but the accumulation and translocation of DEHP by rice (Oryza sativa L.) remains unknown. In the present study, twenty rice cultivars were cultivated in paddy soil spiked with DEHP, and variations in DEHP accumulation and translocation among various cultivars were investigated. Our results showed that DEHP concentrations in roots and shoots of different rice cultivars at four growth stages (i.e., ripening, tillering, jointing, and flowering stages) varied greatly from 0.26 to 11.8 mg/kg (dry weight, dw) and 0.40 to 7.58 mg/kg (dw), respectively. No obvious change over time was observed. The greatest variation in DEHP concentrations among the rice cultivars occurred at ripening stage, whereas the lowest variation at flowering stage. During ripening stage, the largest variation in DEHP concentrations among cultivars were observed in stems (varying from 0.35 to 13.2 mg/kg), whereas the least one was observed in roots (ranging from 1.01 to 5.72 mg/kg). Significant differences in DEHP concentrations in the roots, stems, leaves and grains of most rice cultivars were found. The translocation factors of DEHP from roots to stems or stems to leaves were higher than those from shoots to grains. Overall, cultivars Tianfengyou 316, Wuyou 308, and Peizataifeng, which contained low levels of DEHP in grains but high levels in shoots, were ideal cultivars for simultaneous production of safe food and phytoremediation of contaminated soil.

Influence of phthalates on cytokine production in monocytes and macrophages: a systematic review of experimental trials

Background

Phthalates are a group of endocrine disrupting chemicals suspected to influence the immune system. The aim of this systematic review is to summarise the present knowledge on the influence of phthalates on monocyte and macrophage production and secretion of cytokines, an influence which could affect both pro- and anti-inflammatory abilities of these cells.

Strategy and Results

A systematic search was performed in Medline, Embase and Toxline in June 2013, last updated 3rd of August 2014. Criteria used to select studies were described and published beforehand online on Prospero (http://www.crd.york.ac.uk/NIHR_PROSPERO, registration number CRD42013004236). In vivo, ex vivo and in vitro studies investigating the influence of phthalates on cytokine mRNA expression and cytokine secretion in animals and humans were included. A total of 11 reports, containing 12 studies, were found eligible for inclusion. In these, a total of four different phthalate diesters, six primary metabolites (phthalate monoesters) and seven different cytokines were investigated. Though all studies varied greatly in study design and species sources, four out of five studies that investigated di-2-ethylhexyl phthalate found an increased tumour necrosis factor-α secretion/production from monocytes or macrophages. A summary of cytokine measurements was not possible since few studies were comparable in study design and due to insufficient reporting of raw data for most of the included studies.

Conclusion

Results from this review have suggested that at least one phthalate (di-2-ethylhexyl phthalate) has the ability to enhance tumour necrosis factor-α production/secretion from monocytes/macrophages in vitro, but also observed ex vivo. Influence of other phthalates on other cytokines has only been investigated in few studies. Thus, in vitro studies on primary human monocytes/macrophages as well as more in vivo studies are needed to confirm or dispute these findings.

Status of phthalate esters contamination in agricultural soils across China and associated health risks

The extensive utilization of phthalate-containing products has lead to ubiquitous contamination of phthalate esters (PAEs) in various matrices. However, comprehensive knowledge of their pollution in Chinese farmland and associated risks is still limited. In this study, 15 PAEs were determined in soils from agricultural fields throughout the Mainland China. The concentrations of Σ15PAEs were in the range of 75.0-6369 μg kg(-1). Three provinces (i.e., Fujian, Guangdong and Xinjiang, China) showed the highest loadings of PAEs. Bis(2-Ethylhexyl) phthalate (DEHP) was found as the most abundant component and contributed 71.5% to the ∑15PAEs. The major source of PAEs in arable soils was associated with the application of agricultural plastic films, followed by the activities for soil fertility. Furthermore, the non-cancer and carcinogenic risks of target PAEs were estimated. The hazard indexes (HIs) of PAEs in all samples were below 1 and the carcinogenic risk levels were all within 10(-4). Results from this study will provide valuable information for Chinese agricultural soil management and risk avoidance.

Estimated daily intake and cumulative risk assessment of phthalate diesters in a Belgian general population

The daily intakes (DI) were estimated in a Belgian general population for 5 phthalates, namely diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), di-iso-butyl phthalate (DiBP), butylbenzyl phthalate (BBzP) and di-2-ethylhexyl phthalate (DEHP), based on the urinary measurements of their corresponding metabolites. DI values ranged between <LOD and 59.65 μg/kg bw/day depending on the congener, and were globally higher for children than adults. They were compared to acceptable levels of exposure (tolerable daily intakes) to evaluate the hazard quotients (HQ), which highlight an intake above the dose considered as safe for values greater than 1. If very few of our Belgian participants exceeded this threshold for phthalates considered individually, 6.2% of the adults and 25% of the children showed an excessive hazard index (HI) which took into account the cumulative risk of adverse anti-androgenic effects. These results are of concern since these HI were based on only 3 phthalates (DEHP, DiBP and DnBP), and showed a median of 0.55 and 0.29 for children and adults respectively. The comparison with previously determined dietary intakes demonstrated that for DEHP, food intake was nearly the only route of exposure while other pathways occurred mainly for the other studied phthalates.

Human urinary excretion of non-persistent environmental chemicals: an overview of Danish data collected between 2006 and 2012

Several non-persistent industrial chemicals have shown endocrine disrupting effects in animal studies and are suspected to be involved in human reproductive disorders. Among the non-persistent chemicals that have been discussed intensively during the past years are phthalates, bisphenol A (BPA), triclosan (TCS), and parabens because of their anti-androgenic and/or estrogenic effects. Phthalates are plasticizers used in numerous industrial products. Bisphenol A is the main component of polycarbonate plastics and epoxy resins. Parabens and TCS are antimicrobial preservatives and other phenols such as benzophenone-3 (BP-3) act as a UV-screener, while chlorophenols and phenyl phenols are used as pesticides and fungicides in agriculture. In spite of the widespread use of industrial chemicals, knowledge of exposure sources and human biomonitoring studies among different segments of the population is very limited. In Denmark, we have no survey programs for non-persistent environmental chemicals, unlike some countries such as the USA (NHANES) and Germany (GerES). However, we have analyzed the excretion of seven parabens, nine phenols, and the metabolites of eight different phthalates in urine samples collected over the past 6 years from four Danish cohorts. Here, we present biomonitoring data on more than 3600 Danish children, adolescents, young men, and pregnant women from the general population. Our study shows that nearly all Danes were exposed to the six most common phthalates, to BPA, TCS, and BP-3, and to at least two of the parabens. The exposure to other non-persistent chemicals was also widespread. Our data indicate decreasing excretion of two common phthalates (di-n-butyl phthalate and di-(2-ethylhexyl) phthalate) over time.