Carcinogenic Index Research Articles

Assessment of PAH pollution in mediterranean lakes and health implications for fish and consumers, case study: Manzala Lake, Egypt

This study aims to investigate the distribution, sources, and compositions of 16 polycyclic aromatic hydrocarbons (PAH) in Manzala Lake water and the organs of two fish species: M. cephalus and O. niloticus. In addition, it aims to assess associated health risks and examine protein pattern responses and histopathological lesions in fish from different lake sectors. ∑PAH, ∑COMB, and ∑CAR varied between (0.122–51.895), (0.1–49.63), and (0.08–19.949) μg/L, respectively. Many PAH compounds in the water exceeded the guidelines; benzo[a]pyrene in the muscles of O. niloticus exceeded the European Union (EU) guidelines (2 μg/kg), recording 14.18 and 4.59 μg/kg in the eastern and southern sectors, respectively. In general, the ∑PAH in the muscles of O. niloticus (799.79 ± 26.02 μg/kg) were higher than those of M. cephalus (213.75 ± 8.69 μg/kg) in the eastern sector, which indicates a high potential risk associated with the consumption of O. niloticus. The electrophoresis of protein patterns of the fish muscles recorded site- and species-specific alterations in the proteinogram. M. cephalus exhibited higher sensitivity to PAH but developed a greater tolerance to PAH contamination than O. niloticus. The histopathological investigation reported several lesions in both fish tissue samples, particularly from the southern sector. Fish from Manzala Lake can pose a carcinogenic risk to consumers, mainly O. niloticus, where the PAH4 carcinogenic index was above the EU guidelines (12 μg/kg) in O. niloticus from all sectors. The study highlights lake management's importance in preserving biodiversity and ensuring food safety.

Risk assessment and source analysis of heavy metals in soil around an asbestos mine in an arid plateau region, China

Asbestos is widely used in construction, manufacturing, and other common industrial fields. Human activities such as mining, processing, and transportation can release heavy metals from asbestos into the surrounding soil environment, posing a health hazard to the mining area's environment and its surrounding residents. The purpose of the present study was to determine the extent of ecological and human health damage caused by asbestos pollution, as well as the primary contributors to the contamination, by examining a large asbestos mine and the surrounding soil in China. The level of heavy metal pollution in soil and sources were analyzed using methods such as the geo-accumulation index (Igeo), potential ecological risk index (RI), and positive matrix factorization (PMF) model. A Monte Carlo simulation-based health risk model was employed to assess the health risks of heavy metals in the study area’s soil to human beings. The results showed that the concentrations of As, Pb, Cr, Cu, and Ni in the soil were 1.74, 0.13, 13.31, 0.33, and 33.37 times higher than the local soil background values, respectively. The Igeo assessment indicated significant accumulation effects for Ni, Cr, and As. The RI evaluation revealed extremely high comprehensive ecological risks (RI ≥ 444) in the vicinity of the waste residue heap and beneficiation area, with Ni exhibiting strong individual potential ecological risk (Eir ≥ 320). The soil health risk assessment demonstrated that As and Cr posed carcinogenic risks to adults, with mean carcinogenic indices (CR) of 1.56E − 05 and 4.14E − 06, respectively. As, Cr, and Cd posed carcinogenic risks to children, with mean CRs of 1.08E − 04, 1.61E − 05, and 2.68E − 06, respectively. Cr also posed certain non-carcinogenic risks to both adults and children. The PMF model identified asbestos contamination as the primary source of heavy metals in the soil surrounding the asbestos mining area, contributing to 79.0%. According to this study, it is recommended that management exercise oversight and regulation over the concentrations of Ni, Cr, Cd, and As in the soil adjacent to asbestos mines, establish a designated control zone to restrict population activities, and locate residential zones at a safe distance from the asbestos mine production zone.

Water quality, heavy metal contamination and health risk assessment of surface water bodies of Mohammedia prefecture, Morocco

Research work on surface water bodies in Morocco has been in majority restricted to physicochemical and biological concentration. Hence, this study was conducted to address the existing research gap by evaluating heavy metal contamination and its associated risk assessment in surface water bodies, in Mohammedia prefecture, Morocco. A total of 22 water samples were evaluated regarding physicochemical factors and heavy metals. The parameters analyzed are pH, temperature (T), electrical conductivity (EC), total dissolved solids (TDS), calcium (Ca2+), Sodium (Na+), Potassium (K+), Ammonia (NH+), dissolved oxygen (DO), Sulphate (SO42−), nitrite (NO2−), nitrate (NO3−), phosphate (PO43−), total phosphate (TP), total kjeldahl nitrogen (TKN), cadmium (Cd), copper (Cu), Iron (Fe), lead (Pb), and zinc (Zn). Overall water quality (Ow) and status of contamination presented the water quality and pollution quantitatively. Carcinogenic and noncarcinogenic risks were estimated for health risk assessment. Ca2+ was the most abundant cation, and SO43− was the most abundant anion. Heavy metal concentrations were within permissible limits. Ow was good in terms of being suitable for parameters, i.e., <1 except for NH+. Which indicated water quality in the category of “highly polluted” >2.5. Pollution index (PI) indicated high pollution (14–74) at S3, S4, S5, and S6 sample points. In addition, Pb was a significant contributor to deteriorating water quality, with individual contributions ranging from 1 to 12 at sites S1, S2, and S3. For heavy metal hazards, i.e., adverse health effects, Hazard Quotient (HQ) (0.0002–0.01) was <1 for sample points, and Hazard Index (HI) (0.007–0.01) had a similar trend. They were inferring no significant non-carcinogenic health impact on its consumers. Carcinogenic risk (CR) was found to be within acceptable limits for CD, Cu, Pb, and Zn, i.e., 10−4 to 10−6. At points S2, S3, and S4, the carcinogenic index (CI) was above the acceptable limit, with values ranging from 1 × 10−3 to 7.9 × 10−3 attributed to Fe. Therefore, according to the findings of this research, the water quality is not suitable for direct consumption in its current state. Hence the study recommends treatment of surface water bodies prior to consumption.

Water quality, geochemistry and human health risk of groundwater in the Vyeboom region, Limpopo province, South Africa

This study focuses on the evaluation of trace metals as well as microbial contamination of groundwater. Groundwater samples were collected from 17 boreholes. The microbial quality was tested using membrane filtration method. Higher levels of contamination for both E. coli and total coliform was recorded in the wet season. Majority of the boreholes had nitrate levels above the regulatory guideline value of the World health Organisation and the South African National Standards. The water type was established by Piper plot which showed the predominance of a magnesium bicarbonate water type, with alkaline earth metals dominating the alkali metals, as well as the weaker acids (bicarbonates) dominating the stronger ones (Sulphates and chlorides). Most of the trace metals detected were in compliance with the regulatory standard except for aluminium (0.41–0.88 mg/L). The hazard quotient and Hazard indice exceeded 1 mostly for children in both season which implies a possible non-carcinogenic health risk is associated with the continuous consumption of the water resource. The estimations of carcinogenic risk (CRing) for Cr and Pb exceeded the carcinogenic indices of 10−6 and 10−4 which could pose adverse effects on human health for both children and adults. Therefore, it is recommended that measures should be implemented to reduce the risk.

Isolation and characterization of a newly chrysene-degrading Achromobacter aegrifaciens.

Polycyclic aromatic hydrocarbons (PAHs) are considered substances of potential human health hazards because of their resistance to biodegradation and carcinogenic index. Chrysene is a PAH with a high molecular weight (HMW) that poses challenges for its elimination from the environment. However, bacterial degradation is an effective, environmentally friendly, and cost-effective solution. In our study, we isolated a potential chrysene-degrading bacteria from crude oil-contaminated seawater (Bizerte, Tunisia). Based on 16SrRNA analysis, the isolate S5 was identified as Achromobacter aegrifaciens. Furthermore, the results revealed that A. aegrifaciens S5 produced a biofilm on polystyrene at 20 °C and 30 °C, as well as at the air-liquid (A-L) interface. Moreover, this isolate was able to swim and produce biosurfactants with an emulsification activity (E24%) over 53%. Chrysene biodegradation by isolate S5 was clearly assessed by an increase in the total viable count. Confirmation was obtained via gas chromatography-mass spectrometry (GC-MS) analyses. A. aegrifaciens S5 could use chrysene as its sole carbon and energy source, exhibiting an 86% degradation of chrysene on day 7. In addition, the bacterial counts reached their highest level, over 25 × 1020 CFU/mL, under the conditions of pH 7.0, a temperature of 30 °C, and a rotary speed of 120 rpm. Based on our findings, A. aegrifaciens S5 can be a potential candidate for bioremediation in HMW-PAH-contaminated environments.

The surveillance of arsenic levels in the drinking water of primary schools and the assessment of the potential cancer-related health risks of children in Multan, Pakistan

To investigate the levels of arsenic (As) in the groundwater and drinking water of primary schools and their potential impact on human health is main objective of this study. To assess risk, the following parameters i.e., carcinogenic indices (CI), hazardous indexes (HI), carcinogenic risk (CR), and hazardous quotient (HQ) have been measured for both dermal and oral arsenic exposure. This study has been focused on primary schools located in four tehsils of Multan, where water samples were collected. Arsenic levels, with concentrations ranging from 3.31 to 191 mg/l, exceeding the safe limit set by the World Health Organization (WHO) have been detected in 99.9% of the samples. The results show that arsenic content ranged from 3.31 to 191 mg/l, with 99.9% of the samples exceeding the World Health Organization's safe limit of 10 mg/l. The CR and CI exceeded the USEPA limit of 10–6 in all four tehsils ranged from 2.6 × 10-6 to 9.4 × 10-6 and 0.00023 to 0.0009 respectively in both dermal and oral cases. , Multan Sadar (1.51, 1.39) and Multan City (1.76, 1.71) exhibited HI and HQ values that surpassed the threshold of 1.0, signaling a significant likelihood of chronic and cancer-causing health consequences for individuals who are exposed to polluted water causing health. The findings suggest that the groundwater in the Multan district poses a significant health risk to humans due to high levels of arsenic contamination. This contamination is associated with an increased risk of mortality from internal cancers (including liver, kidney, lung, and bladder), as well as a higher HI & CI incidence of skin cancer. Furthermore, pregnancy outcomes are affected, with associations found between arsenic exposure and lower birth weight, and infant mortality. The researchers propose that water supply organizations and educational institutions promptly take measures to ensure that the affected areas have access to arsenic-free drinking water for the well-being of students and residents.

Source Apportionment and Risk Estimation of Heavy Metals in PM10 at a Southern Vietnam Megacity

Airborne particulate matter (PM) pollution is a global concern, in which partitioned heavy metals (HMs) could impose great risks to residents living in metropolitan areas. In this study, PM10 samples were collected in Ho Chi Minh City (HCMC) – a megacity in southern Vietnam – and analyzed for 11 HMs to investigate their concentration profiles, perform source apportionment and estimate their risk factors. Results showed that atmospheric HMs concentration decreased following the order of Al > Fe > Sr > Mn> Pb > Cu > Cr > V > Ni > Sb > As. Traffic activities were likely the major cause of rush-hour peaks for most HMs in which Cr, As, and Cu showed > 20% increases in their relative proportions. For seasonal variation, most HMs showed a dry > rainy pattern as a result of washout by higher rainfall in the rainy season while crustal elements (Al, Sr, Mn) showed a rainy > dry pattern and might be explained by the difference in air mass transport modulating by monsoon activities. The positive-matrix factorization (PMF) model revealed 5 primary sources for HMs, including traffic emission, shipping activity and combustion activity, fugitive dust re-suspension and waste incineration. Combustion activity might enrich As, Sb, Pb levels at HCMC, and As contributed half (50.8%) to the potential ecological risk (PER) in the city. Besides, the current Cr level could impose a carcinogenic effect towards children in HCMC (total carcinogenic index > 10-4) while Mn might impose intolerable non-carcinogenic risk (hazard index > 1). This study provides information on local air quality status for scientific and regulatory perspectives as well as helps fill the information gap and update the understanding of air pollution in South and Southeast Asia.

Macroalgae in biomonitoring of metal pollution in the Bay of Bengal coastal waters of Cox\u2019s Bazar and surrounding areas

Although coastal water marine algae have been popularly used by others as indicators of heavy metal pollution, data within the Bay of Bengal for the estuarine Cox’s Bazar region and Saint Martin’s Island has remained scarce. Using marine algae, the study herein forms an effort in biomonitoring of metal contamination in the aforementioned Bangladesh areas. A total of 10 seaweed species were collected, including edible varieties, analyzed for metal levels through the use of the technique of EDXRF. From greatest to least, measured mean metal concentrations in descending order have been found to be K > Fe > Zr > Br > Sr > Zn > Mn > Rb > Cu > As > Pb > Cr > Co. Potential toxic heavy metals such as Pb, As, and Cr appear at lower concentration values compared to that found for essential mineral elements. However, the presence of Pb in Sargassum oligocystum species has been observed to exceed the maximum international guidance level. Given that some of the algae species are cultivated for human consumption, the non-carcinogenic and carcinogenic indices were calculated, shown to be slightly lower than the maxima recommended by the international organizations. Overall, the present results are consistent with literature data suggesting that heavy metal macroalgae biomonitoring may be species-specific. To the best of our knowledge, this study represents the first comprehensive macroalgae biomonitoring study of metal contamination from the coastal waters of Cox’s Bazar and beyond.

Probabilistic health risk assessment and concentration of trace elements in meat, egg, and milk of Iran

ABSTRACT This research was performed to assess the concentration and health risk of eight trace elements (manganese (Mn), mercury (Hg), copper (Cu), lead (Pb), iron (Fe), zinc (Zn), cadmium (Cd), and arsenic (As)) in animal product samples (n = 120) in Markazi province of Iran by inductively coupled plasma optical emission spectrometry (ICP-OES). Some trace elements such as Mn, Hg, Cu, Pb, Fe, and Zn were detected in samples while Cd and As non-detected. Fe had the highest mean level of trace elements in meat samples (1551.28 ± 83.25 μg/kg). The levels of Pb and Hg in some samples were upper than the limit of the European Commission (EC) and the Institute of Standards and Industrial Research of Iran (ISIRI), International/National Standards for Heavy Metals, and U.S. Food and Drug Administration (FDA). Deterministic and probabilistic health risk assessment approaches to evaluate of the target hazard quotients (THQ) and carcinogenic risks (CR) index were applied. The Monte Carlo probability distributions revealed that the rank order of total target hazard quotient (TTHQ) was milk > meat > egg. The non-carcinogenic and carcinogenic index of toxic elements indicated that exposed population in Markazi province was safe (1> THQ, 10−4> CR), except Hg exposure for children in milk.

Polycyclic Aromatic Hydrocarbons in Indoor Dust Collected during the COVID-19 Pandemic Lockdown in Saudi Arabia: Status, Sources and Human Health Risks.

To control the spread of coronavirus disease (COVID-19), Saudi Arabia’s government imposed a strict lockdown during March–July 2020. As a result, the public was confined to indoors, and most of their daily activities were happening in their indoor places, which might have resulted in lower indoor environment quality. Polycyclic aromatic hydrocarbons (PAHs) were analyzed in household dust (n = 40) collected from different residential districts of Jeddah, Saudi Arabia, during the lockdown period. PAHs’ levels were two folds higher than the previously reported PAHs in indoor dust from this region. We detected low molecular weight (LMW) with two to four aromatic ring PAHs in all the samples with a significant contribution from Phenanthrene (Phe), present at an average concentration of 1590 ng/g of dust. Although high molecular weight (HMW) (5–6 aromatic ring) PAHs were detected at lower concentrations than LMW PAHs, however, they contributed >90% in the carcinogenic index of PAHs. The estimated daily intake (EDI) of specific PAHs was above the reference dose (RfD) for young children in high-end exposure and the calculated Incremental Lifetime Cancer Risk (ILCR) was >1.00 × 10−4 for both Saudi adults and young children. The study highlighted that indoor pollution has increased significantly during lockdown due to the increased indoor activities and inversely affect human health. This study also warrants to conduct more studies involving different chemicals to understand the indoor environment quality during strict lockdown conditions.

Surface and Groundwater Pollution: the Invisible, Creeping Threat to Human Health

Abstract This study reports pollution source apportionment of surface waters and human health risk assessment based on 18 physicochemical and traces elements from 24 water quality monitoring sites for surface and groundwater around the two trans-boundary rivers of Pakistan: The Ravi and Sutlej. The principal component analysis identified 6 principal components (76.98 % cumulative variance) which are mainly caused by untreated industrial effluents, intense agricultural activities, and irrigation tailwater discharges. For all dissolved trace elements in surface waters, health hazard indices (HI) and hazard quotients (HQ) through ingestion and dermal contact are &lt; 1 except As and Cr through ingestion only (for both adults and children). For adults and children, the HQingestion and HI values for As, Mn, Cu (for children only) and As, Fe, Mn (for children only) are &gt; 1, indicating that As, Mn, Fe, and Cu are the most important pollutants causing chronic risks among the selected trace elements in both shallow and deep groundwater respectively. HQingestion, HQdermal, and HI values are higher for children than that of adults which shows the high susceptibility of children to these dissolved trace elements. The carcinogenic indices for the entire surface water elements exceed 10−6 through dermal and ingestion pathways suggesting carcinogenic health risk to the surrounding community. Hence, to protect human health, wastewater treatment plants and best management practices should be practiced to control point source and nonpoint source pollution respectively in the understudied area.

Charcoal-barbecued Coalho cheese: An investigation on the formation and ingestion of polycyclic aromatic hydrocarbons

The objective of this study was to determine polycyclic aromatic hydrocarbons (PAH) in Coalho cheese samples (CC, n = 30) barbecued in charcoal at different distances (5, 15, or 20 cm). PAH were determined using liquid-liquid extraction (LLE) followed by gas chromatography-mass spectrometry (GC-MS). The CC samples presented all the 16 PAH monitored by the health agencies, including 8PAH considered as the most toxic. The benzo [a]anthracene (BaA) and dibenz [a,h]anthracene (DBA) levels were determined, which ranged from 140.7 to 149.4 μg kg−1 to 135.0–139.5 μg kg−1, respectively. The toxicity values showed that the human exposure to PAH in the preparation and consumption of CC is classified as a serious risk or potential risk to cause cancer in humans, with levels higher than 83% and 69% for BaA and DBA, respectively, which are the compounds with the highest carcinogenicity index. The distance to the heat source had no effect on the parameters evaluated. Thus, CC presented high concentrations of PAH and potential risk for the health of Brazilian consumers. Therefore, consumers should be aware of the type of preparation and consider the condition of lightly toasted CC as a food-safe and appropriate consumption profile.

Characteristics of Volatile Organic Compounds during Different Pollution Periods in Winter in Yuncheng, a Typical City in North China

ABSTRACT The composition characteristics and health risks of volatile organic compounds (VOCs) and their effects on secondary organic aerosol (SOA) during polluted and clean periods in winter 2018 for Yuncheng, a typical city in North China, were studied. The average concentration of VOCs was 2.3 times higher during the polluted period (105.29 µg m–3) than the clean period (45.78 µg m–3), whereas the average concentrations of the alkanes, alkenes, and aromatics were 3.4, 2.1, and 3.9 times higher, respectively, during the polluted period than the clean period. In addition, the VOC concentration was significantly influenced by meteorological conditions. Using positive matrix factorization (PMF), seven sources of atmospheric VOCs were identified, with the largest factors being vehicle emission (27.89%), coal combustion (23.37%), liquefied petroleum gas/natural gas evaporation (18.30%), and industrial emission (15.51%). Vehicle emission (30.04%) was the primary contributor during the polluted period, whereas coal combustion (33.53%) was the primary contributor during the clean period. The SOA formation potential (which almost exceeded 80%) was influenced by industrial emission (28.80%), solvent usage (26.30%), and vehicle emission (24.85%). Additionally, an assessment of the health risks of six aromatics based on the health risk exposure model of the United States Environmental Protection Agency revealed that the non-cancer risk was higher during the polluted period (6.61 × 10–2) than the clean period (2.20 × 10–2) but still below the Environmental Protection Agency (EPA) limit (1.00) and therefore negligible for the exposed population. However, the carcinogenic index of benzene (2.85 × 10–5 to 5 × 10–5) exceeded 10–6, suggesting a higher carcinogenic risk. Large-scale energy restructuring during recent years has sharply reduced coal combustion, but the VOC concentration has dramatically increased due to vehicle emission. Hence, regulating vehicle emissions is an effective strategy for controlling VOCs in Yuncheng.

Monitoring of arsenic in drinking water of high schools and assessment of carcinogenic health risk in Multan, Pakistan

This study was performed to measure arsenic (As) contents in groundwater/drinking water of high schools and its effects on human health. Chronic daily intake, hazardous quotient (HQ), carcinogenic risk (CR), hazardous index (HI), and carcinogenic indices (CI) for oral and dermal exposure to arsenic were calculated. Samples were taken from high schools in four tehsils of Multan. As contents ranged from 3.25 to 184 µg/l and 99% samples exceeded World Health Organization safe limit (10 µg/l). HQ for Multan city (1.70) and for Multan Saddar (1.38) exceeded USEPA permissible toxic risk value (1.0). CR in four tehsils for oral (0.0001–0.0003) and dermal exposure (0.0000049–0.000011) exceeded USEPA limit (10−6). HI for tehsil Multan city (1.75) and Multan Saddar (1.42) exceeded the limit (1.0). CI for four tehsils ranged from 0.00022 to 0.0008 exceeding USEPA limit (10−6) indicating high chronic and carcinogenic health risk to exposed population. Results indicated that groundwater of district Multan is not fit for human consumption due to excessive arsenic contamination. It invites attention of water supplying agency and educational authorities to take steps for provision of arsenic free safe drinking water to students and local area peoples.

Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Commonly Consumed Shellfish from Kula, Rivers State, Nigeria

Polycyclic Aromatic Hydrocarbons (PAHs) were assessed in shellfishes (whelk, oyster and periwinkle) from Kula, Rivers State, Nigeria. The PAHs determination was done using gas chromatography (GC) coupled with flame ionization detector (FID) (Hewlett Packard, Wilmington, DE, USA), powered with HP chemstation Rev. A09:01 (10206) software. Human health risk assessment models based on United States Environmental Protection Agency (USEPA) was used to characterize risks of PAHs exposure to non cancer (Hazard Index) while and excess cancer risk (ECR). From the results, Benzo [a] Anthrancene (BaA) had highest concentrations in whelk (0.689±0.003) and Periwinkle (0.930±0.001) while Naphthalene had highest concentration in oyster (2.000±0.000). The Total concentration of PAHs in µ g/kg for whelk, oyster and periwinkle were 1.797±0.013, 3.977 ±0.024 and 1.564±0.017 while the estimated daily intake (EDI) of PAHs (mg/kg/day) via consumption of shell fish ranged from 2.00x10-4 to 6.40x10-2, 7.0x10-4 to 1.86 x10-1 and 0 to 8.64x10-2 far above oral reference dose (RFD) respectively. The toxic equivalents (TEQs) values were 1.276x10-4, 1.252x10-4 and 4.034x10-4 for whelk, oyster and periwinkle respectively, were significantly (p&lt;0.05) higher than the screening value (SV) for shellfish 1.81x10-5mg/kg. The estimated excess cancer risk (ECR) obtained for whelk was (3.0x10-4), oyster (2.00x10-4) and periwinkle (3.24x10-4). These values were far above the USEPA acceptable (1x10-4). From this study, it can be deduced that bioaccumulation of PAHs in the shellfish is a potential health hazard to consumers. Carcinogenic indices indicated that daily Intake of contaminated shellfishes exposures the local populace to cancer risks.

A multi-elemental approach to assess potential contamination in tourist beaches: The case of Loreto Bay (Marine Protected Area), NW Mexico

Metal/metalloid concentrations in water sediment and commercial fishes of Loreto Maritime National Park (MNP), Baja California Sur, Mexico were determined for a comprehensive geochemical study. In-situ physical characteristics (pH, conductivity, redox potential, dissolved oxygen, turbidity) of water clearly indicated the unique oceanographic properties of the Gulf of California. Likewise, the distribution pattern of metals/metalloid in water, sediments and fishes denoted the influences of local geology, longshore currents, upwelling process, natural hydrothermal vents and the 100-year old mining activities of Santa Rosalia region, situated to the north of Loreto. Calculated carcinogenic indices in commercial fish species showed safe human consumption. Thus, the present research validates a comprehensive geochemical study of protected areas upholding the need for continuous monitoring for a better conservation of coastal ecosystems.

VOCs characteristics and their relation with rheological properties of base and modified bitumens at different temperatures

During heating process of bituminous materials, volatile organic compounds (VOCs) will be released, and it is harmful to the skin, the respiratory and nervous system of the human body, especially increasing its carcinogenic tendency. In this study, the VOCs emission of base and modified binder was characterized as the function of typical temperatures by gas chromatography coupled with mass spectrometry (GC/MS). The rheological behavior of each binder before and after the emission of VOCs was compared. The relation between the VOCs emission of bitumen and its rheological properties was researched. The results indicated that a higher temperature can lead to increase of VOCs components of binder. The addition of SBS modifier can reduce VOCs components of its base binder. However, the degradation of the SBS modifier decreased its inhibition effect on the VOCs emission of bitumen at 220 °C. Naphthalene release and carcinogenic index of polycyclic aromatic hydrocarbons (PAHs) increased with the increase of temperature. The complex-flow activation energy Ea increased after VOCs emission. Naphthalene content exhibited a better linear relation with Ea.

Carcinogenic ability quantification of human papilloma virus subtypes in eastern China.

Human papilloma virus (HPV) infection is a precursor of cervical cancer. This study aimed to introduce a method to quantify the risk of cervical cancer resulting from infection by different HPV subtypes, to help guide patient treatment. Nucleic acid molecule flow-through hybridization and gene chip technology were used to test 6,510 non-cervical cancer healthy volunteers (≤CIN-I) and 204 cervical cancer patients (≥CIN-III) from Dongying City for 21 HPV subtypes (HPV-16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 6, 11, 42, 43, 44, 53, 66 and CP8304) in exfoliated cervical cells. The positive proportion of HPV subtypes was calculated, excluding or including patients with multiple subtype infections. The lower (L) and upper (H) limits of the carcinogenic risk score range were calculated, respectively. The values of carcinogenic index ± uncertainty in the carcinogenic ability (CI ± U) were also calculated. CI = (H + L)/2 represents the carcinogenic risk of the different subtypes, and U =(H - L)/2 represents the probability of each subtype being present in multiple infections. Infection rates were 15.87 and 96.57%, and HPV subtypes with high infection rates were HPV-16, 52, 58, 33, 18, and 31 and HPV-16, 31, 58, 18, 68, and 33 in the non-cervical cancer and cervical cancer groups, respectively. HPV subtypes with high risk of cervical cancer were HPV-31 (3.71 ± 0.68), 51 (2.65 ± 0.44), 18 (2.03 ± 0.43), 68 (1.76 ± 0.40), 58 (1.68 ± 0.49), and 16 (1.39 ± 0.33). We have provided a quantitative method for expressing HPV subtype carcinogenic risk.

Assessment of the water chemical quality improvement based on human health risk indexes: Application to a drinking water treatment plant incorporating membrane technologies

A methodology has been developed in order to evaluate the potential risk of drinking water for the health of the consumers. The methodology used for the assessment considered systemic and carcinogenic effects caused by oral ingestion of water based on the reference data developed by the World Health Organisation (WHO) and the Risk Assessment Information System (RAIS) for chemical contaminants. The exposure includes a hypothetical dose received by drinking this water according to the analysed contaminants. An assessment of the chemical quality improvement of produced water in the Drinking Water Treatment Plant (DWTP) after integration of membrane technologies was performed.Series of concentration values covering up to 261 chemical parameters over 5years (2008–2012) of raw and treated water in the Sant Joan Despí DWTP, at the lower part of the Llobregat River basin (NE Spain), were used. After the application of the methodology, the resulting global indexes were located below the thresholds except for carcinogenic risk in the output of DWTP, where the index was slightly above the threshold during 2008 and 2009 before the upgrade of the treatment works including membrane technologies was executed. The annual evolution of global indexes showed a reduction in the global values for all situations: HQ systemic index based on RAIS dropped from 0.64 to 0.42 for surface water and from 0.61 to 0.31 for drinking water; the R carcinogenic index based on RAIS was negligible for input water and varied between 4.2×10−05 and 7.4×10−06 for drinking water; the W systemic index based on the WHO data varied between 0.41 and 0.16 for surface water and between 0.61 and 0.31 for drinking water. A specific analysis for the indexes associated with trihalomethanes (THMs) showed the same pattern.

Human Health Risk from Metals in Fish from Saudi Arabia: Consumption Patterns for Some Species Exceed Allowable Limits

ABSTRACTFish are a healthful source of protein, but contaminants in some fish pose a risk. While there are multiple risk assessments from Europe and North America, there are far fewer for other parts of the world. We examined the risks from mercury, arsenic, lead, and other metals in fish consumed by people in Jeddah area, Saudi Arabia, using site-specific data on consumption patterns and metal levels in fish. The U.S. Environmental Protection Agency's Hazard Quotient (HQ) and cumulative Hazard Index (HI) for non-cancer endpoints and Carcinogenic Index for cancer were used to determine the health risk based on fish consumption rates. Of the 13 fish species examined, HQ was greater than 1 (indicating elevated risk) in two species for arsenic, and seven species for methylmercury. The cumulative HI for all metals was above 1 for all but three species of fish at the mean consumption rates. Generally, fish species with HI above 1 for one sampling location, had HI above 1 for all sampling locations. The implications of these findings are discussed in the light of strategies for reducing risk from fish consumption while encouraging dietary intakes of fish with low mercury and arsenic levels.