Lulwa Ali

Levels and profiles of organochlorines and flame retardants in car and house dust from Kuwait and Pakistan: implication for human exposure via dust ingestion.

There are only few studies documenting indoor pollution in the Middle East and the Indian subcontinent. In present study, we have evaluated the occurrence of various organochlorines (OCs) and flame retardants (FRs) in dust from cars and houses of Pakistan and Kuwait. Polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), organophosphate FRs (PFRs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were investigated in indoor dust from urban houses (N=15 per country) and cars (N=15 per country). PFRs were the major analytes in all four microenvironments, followed by PBDEs>NBFRs>OCPs>PCBs. For all classes of analytes, relatively lower levels were observed in car and house dust from Pakistan than Kuwait. Levels of ∑PBDEs, ∑NBFRs and ∑PFRs were higher in car dust, while ∑OCPs and ∑PCBs were higher in house dust from both countries. ∑PFRs occurred at average concentrations of 16,900, 87,900, 475, and 2500ng/g in Kuwaiti house and car, and Pakistani house and car dust, respectively. For both countries, the profiles of analytes in car dust were different from those in the house dust. Different exposure scenarios using 5th percentile, median, mean, and 95th percentile levels were estimated for adult, taxi drivers and toddlers. For Kuwaiti toddlers, assuming high dust intake and mean and 95th percentile concentrations, the values computed for ∑OCPs (1500ng/kg bw/day) were higher than RfD values, while for ∑PCBs (14.5ng/kg bw/day) it was only two-fold lower than the corresponding RfDs.

Polycyclic aromatic hydrocarbons (PAHs) in indoor dust samples from Cities of Jeddah and Kuwait: Levels, sources and non-dietary human exposure

This study reports levels and profiles of polycyclic aromatic hydrocarbons (PAHs) in dust samples collected from three different microenvironments (cars, air conditioner (AC) filters and household floor dust) of Jeddah, Saudi Arabia (KSA) and Kuwait. To the best of our knowledge, this is first study reporting PAHs in indoor microenvironments of KSA, which makes these findings important. Benzo(b)fluoranthene (BbF), benzo(a)pyrene (BaP), phenanthrene (Phe), and pyrene (Pyr) were found to be the major chemicals in dust samples from all selected microenvironments. ΣPAHs occurred at median concentrations (ng/g) of 3450, 2200, and 2650 in Saudi AC filter, car and household floor dust, respectively. The median levels (ng/g) of ΣPAHs in Kuwaiti car (950) and household floor (1675) dust samples were lower than Saudi dust. The PAHs profile in Saudi dust was dominated by high molecular weight (HMW) (4-5 ring) PAHs while in Kuwaiti dust 3 ring PAHs have marked contribution. BaP equivalent, a marker for carcinogenic PAHs, was high in Saudi household floor and AC filter dust with median levels (ng/g) of 370 and 455, respectively. Different exposure scenarios, using 5th percentile, median, mean, and 95th percentile levels, were estimated for adults and toddlers. For Saudi and Kuwaiti toddlers worst exposure scenario of ΣPAHs was calculated at 175 and 85ng/kg body weight/day (ng/kgbw/d), respectively. For Saudi toddlers, the calculated worst exposure scenarios for carcinogenic BaP (27.7) and BbF (29.3ng/kgbw/d) was 2-4 times higher than Kuwaiti toddlers. This study is based on small number of samples which necessitate more detailed studies for better understanding of dynamics of PAHs in the indoor environments of this region. Nevertheless, our finding supports the ongoing exposure of organic pollutants to population that accumulates indoor.

Seasonal variations in the atmospheric concentrations of polybrominated diphenyl ethers in Kuwait.

The study reports fortnightly atmospheric concentrations of PBDEs concomitantly measured at an urban and a remote location over a twelve-month period in Kuwait to examine seasonal variability and urban-rural concentration gradients. The annual mean (and range) of ∑PBDE concentrations was 32 (3-208) pgm(-3) at the remote site and 57 (0.3-445) pgm(-3) at the urban site. Although not statistically significant, the median (29 pg m(-3)) and mean (57 pg m(-3)) concentrations at the urban location were higher than those measured at the remote location (18 and 29 pg m(-3) respectively), consistent with the view that urban centers are an important net source of these compounds to the environment. Although Clausius-Clapeyron plots showed statistically significant correlations (p<0.05) with temperature for low molecular weight congeners (BDEs 28, 47, 100), correlations with the ΣPBDE concentrations were not significant at both urban and remote sites. The seasonal variations in ΣPBDE concentrations were not markedly different at the urban location, but the median summer ΣPBDE concentration at the remote location was significantly higher than winter median ΣPBDE concentrations. The absence in seasonality at the urban location may be due to ongoing primary emissions in urban areas.

POLYCYCLIC AROMATIC HYDROCARBONS IN THREE VARIETIES OF FISH FROM KUWAIT BAY

The study reports levels of parent polycyclic aromatic hydrocarbons (PAHs) in three native fish species—mullet, sea bream and tonguesole—captured from Kuwait Bay (KB) area and outside the Bay from the Auha area between October 2004 and June 2005. KB has witnessed rapid urban and industrial development since the discovery of oil and is considered to be the most productive area in the region. Whole fish analysis revealed that the lower molecular weight PAHs (pyrene, fluoranthene and phenanthrene) were present in all the three varieties of fish in considerably higher amounts. Other low molecular weight PAHs like acenaphthylene, acenaphthene and anthracene were also present but in lower concentrations. Among the higher molecular weight PAHs, the frequency of detection of benzo(a)anthracene and chrysene was high and were present in high concentrations, whereas Benzo(k)fluoranthene and benzo(a)pyrene were not frequent in detection. The contamination of Σ PAHs was higher in the winter season in mullet and sea bream but in tonguesole a reverse pattern was found. Tonguesole from KB had the highest Σ PAHs suggesting that this bottom dwelling species can be used as an indicator of sediment pollution in the area. The observed seasonality in ∑ PAHs concentration in fish coupled with species difference may be related to difference in metabolic disposition of pollutants and their habitats.

The Effect of Temperature on the Composition and Relative Toxicity of the Water-Soluble Fraction of Kuwait Crude Oil (Export) in the Seawater

Abstract The effect of temperature on the composition of the water-soluble fraction (WSF) of Kuwait crude oil was investigated. The results showed that the WSF consisted of mostly monoaromatic (BTEX) compounds. The total concentration of volatiles in the WSF was about 7.5 mg/1. The increase in the temperature from 15°C to 25°C caused an increase of about 10% and to 35°C did not significantly affect the total concentration. GC-MS analysis of the concentrated extract of the WSF resulted in the identification of nine PAHs and six methylated PAHs. The total concentration of the PAHs ranged from 0.217 mg/1 to 0.634 mg/1. The PAHs increased significantly with increasing temperature. Naphthalene and methylated naphthalenes constituted about 95% of the total PAHs. Microtox assay of the WSF showed that the relative toxicity increased when the temperature was increased from 15° to 25°C. Increasing temperature further to 35°C did not effect the relative toxicity.

Polybrominated diphenyl ether levels in dust collected from cars in Kuwait: Implications for human exposure

Polybrominated diphenyl ethers (PBDEs) are semivolatile organic compounds (SVOCs) with a ubiquitous environmental distribution. Their presence in cars is linked to their use as flame retardants in electronic items and instrument panels, high-impact plastics, foam and fabric of car seats. The goal of this study was to investigate the occurrence and concentration of PBDEs in dust samples collected from 19 randomly selected cars in normal use in Kuwait and to assess human non-dietary ingestion exposure to these compounds. The concentrations of the total target PBDEs, Σ14PBDEs, were log normally distributed and ranged from 68 to 17,200 ng/g. BDE-209 was the dominant congener in all cars examined with concentrations ranging from 52 to 16,100 ng/g which, on average, accounted for 77% of the Σ14PBDEs measured. Using the measured concentrations the estimated human non-dietary ingestion exposure based on median PBDE concentrations ranged from 0.034 ng/kg-bw/day for adults to 0.138 ng/kg-bw/day for toddlers. The exposure estimate for drivers was the highest at 0.170 ng/kg-bw/day. This study supports the previous findings of photolytic debromination of BDE-209 to lower brominated congeners known to be more bioaccumulative and toxic.

Organohalogenated contaminants in sediments and bivalves from the Northern Arabian Gulf

Several classes of Organohalogenated contaminants (OHCs) were determined in sediments and bivalves collected from Kuwait coast. The levels and profile of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) were compared in both sediments and bivalves. PCB-153 and -138 were the major contributors towards total OHCs followed by DDT and its metabolites (DDTs). The higher contribution of DDTs (~40%) and BDE-47 (~15%) in bivalves as compared to that in associated sediments indicated high biota-sediment accumulation factors (BSAF). Higher BSAF (values for heavier PCBs, DDTs and PBDEs) also indicated their high accumulation potential from sediment into associated biota at most of the studied locations. Overall, OHCs in sediments and bivalves measured in current study were lower than those reported in the literature worldwide. Most of the sediment concentrations of OHCs (ng/g, dry weight) were in the range of permissible guideline values proposed by Canadian Sediment Quality Guidelines (CSQGs), with few exceptions for DDTs (5 ng/g) and PCBs (22.7 ng/g). Similarly, 10% of bivalve samples contained high levels (ng/g, lipid weight) of PCBs (300) and DDTs (150) and were above the set safety benchmarks. This study establishes baseline for future monitoring programs.

Trace metal speciation in marine sediments from Sulaibikhat Bay, Kuwait

The chemical speciation of trace metals (Cd, Co, Cr, Cu, Ni, Pb and Zn) in marine sediments from Sulaibikhat Bay, Kuwait was determined using a three-step sequential extraction procedure. To obtain a mass balance, a fourth step, i.e. digestion and analysis of the residue was undertaken using a microwave-assisted acid digestion procedure. The sum of the 4 steps (acid-soluble + reducible + oxidizable + residual) was in good agreement with the total content (71–116%), suggesting that the microwave extraction procedure is efficient. The results showed that all metals except for Pb and Zn were present at higher percentages in the residual fraction. The reducible fraction was the next followed by the oxidizable fraction. The exchangeable fraction was least important as a host for most metals. The mobility order of exchangeable fraction of the elements in surface sediments decreased in the order Cd > Zn > Cu > Co > Pb > Ni > Cr; the reducible fraction in the order Pb > Zn > Cu > Cd > Co > Ni > Cr; the oxidizable fraction in the order Pb > Cu > Cd > Ni > Co > Zn > Cr, and the residual fraction in the order Cr > Ni > Co > Cu > Cd > Zn > Pb. The data showed that the speciation of trace elements in sediments close to a sewage outfall was different from that of sediment from other parts of Sulaibikhat Bay. This suggests that the contribution of the sewage outfall to metal pollution in adjacent marine area is positive and is associated with fine-grained sediments with high level of organic content, which are major controlling factors for the distribution of trace metals in this part of the Bay.