Urinary Level of Dimethoate, Bisphenol a and Benzo[a]pyrene in the First-year Students of Hohai University From Different Geographical Regions

doi:10.21203/rs.3.rs-400314/v1

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Urinary Level of Dimethoate, Bisphenol a and Benzo[a]pyrene in the First-year Students of Hohai University From Different Geographical Regions

https://doi.org/10.21203/rs.3.rs-400314/v1

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Background: The objective of this study was to detect the urinary level of dimethoate, benzo(a)pyrene (BaP), and bisphenol A (BPA) in the first-year Hohai University students of different geographic origins.

Methods: First-morning urine samples were collected from 540 healthy freshmen aged 17 to 19. Toxin levels were measured using β-glucuronidase hydrolysis followed by a high-performance liquid chromatography-tandem mass spectrometry-based method. Geometric means (GM) are presented by BMI (Body Mass Index) and different locations for these three toxins in a volume-based and creatinine-standardized way.

Results: GM concentration of dimethoate, BPA and BaP were 9.47 µg/L (10.80 µg/g creatinine), 3.54 µg/L (4.04 µg/g creatinine) and 0.34 ng/L (0.39 ng/g creatinine), respectively. The GM concentration of dimethoate in males was significantly higher than that in females. The BMI higher than 23.9 had a higher GM concentration of dimethoate, BPA, and BaP. The inhabitant in the Southwest of China had a significantly lower GM concentration of dimethoate, BPA, and BaP than those who live in other locations of China.

Conclusion: The average level of environmental toxins accumulation in freshmen is relatively high and differs in the youth who live in different regions. Besides, obesity is correlated to higher toxins levels in youth.

Health Economics & Outcomes Research

Other Public Policy

Dimethoate

Benzo(a)pyrene

Bisphenol A

Exposure

First-year students

Pollution problems of air, water, and food have been increasing as a consequence of global climate change, pesticide misuse, and industry development[1], thus the negative effects of environmental pollution on human health have lately become a great concern. Inevitably, humans are exposed to pollutants such as heavy metals, pesticide residues, polycyclic aromatic hydrocarbons (PAHs), bisphenol A (BPA), and so on through drinking water, food, dust, and ambient air[2] which tightly link to the initiation and progression of multiple diseases[3].

China is one of the largest agricultural countries in the world, with >300,000 tons of agricultural pesticides used annually[4]. Dimethoate, one of the most commonly used organophosphorus pesticides, is wildly used for broad-spectrum control of a wide range of insects including mites, flies, aphids, and plant hoppers[5]. Overuse of dimethoate can lead to massive residues on fruits, vegetables, and grains [6]. Existing research confirmed that even very low levels of dimethoate may have adverse health effects[7, 8] which is potentially carcinogenic[9, 10]. At the same time, the extensive industrial development model has made China fall into an “environmental pollution–economic development” cycle[11]. PAHs, which are originated from diverse sources including petrochemical products and the combustion of fossil fuels, are pervasive pollutants characterized by their hazardous carcinogenic and mutagenic potential which exist not only in the air but also in food and drinking water[12, 13]. Benzo(a)pyrene (BaP) is one of the most studied PAHs classified by IARC as a Group 1 carcinogen[14]. Multiple studies have shown that BaP requires metabolic activation to exert its carcinogenic effects[15, 16]. It was reported that a higher incidence of forestomach tumors was observed when applied with BaP in food to B6C3F1 mice over a lifetime[17]. BPA is a synthetic plasticizer with more than 8 million pounds produced worldwide each year which can be found everywhere from plastic bottles, the medical devices to the undercoat of the food packages[18]. Likewise, there is growing evidence that BPA may adversely affect human health. Several studies have proved that BPA has negative effects on human reproduction including female fertility[19], male sexual function[20], sperm quality[21], etc. Moreover, BPA has an impact on gene expression processes, such as the enzymatic proteins which have important roles during fetal development[22]. Besides, metabolic syndromes such as type 2 diabetes, non-alcoholic fatty liver disease, and obesity are also associated with BPA[23].

Different subjects originating from distinct parts of the country may carry the pattern of environmental exposure in their regions. It was reported that the blood Pb levels of the populations who live in Wuhan of central China were lower than those in Beijing[24]. It was also reported that the healthy Chinese who live in the mining area of manganese mines or nonferrous metal mines have a significantly higher urinary manganese level than those who live in other regions. Another study showed that higher urinary levels for As and Cd in the Wuhan population are observed when compared with other countries[25]. Besides the geographic distributions, a preliminary study has reported that the hair and urinary Al levels in the obese subjects are significantly higher by 31% and 46% compared to that in the healthy group, respectively[26].

Hohai University (former Hohai Civil Engineering School of China, established in 1915, HHU) is a national key university under the direct administration of the Ministry of Education. As a comprehensive university with at least 20 colleges, she enrolls more than tens of thousands of students each year from every province in China. Before entering university, the lifestyle of high school students is relatively unitary during nearly 10 years study period at the place of birth. Considering that environmental background may have a significant effect on long-term health effects. Meanwhile, these environmental toxin markers can be easily detected in blood and urine. It’s meaningful to detect the level of environmental toxin which could reflect the local environment and individual health.

Therefore, the objective of the present study was to provide the baseline information of the levels of dimethoate, BaP, and BPA in the urine samples from the first-year Hohai University students of different geographic origins and to assess the correlation between the level of pollutants exposure with geographic origins and BMI through the baseline. More importantly, it will facilitate the improvement of the overall health level of Chinese people by advocating a healthier lifestyle and provide suggestions for environmental protection policy design.

Study Design and Participants

All procedures including sampling and examination were performed in agreement with the principles set in the Declaration of Helsinki and its later amendments (2013). All examinees were invited to participate and took part in the present study voluntarily. All subjects were informed about the objectives of the study and experimental procedures and signed the informed consent form. The study protocol has been reviewed and approved by the Ethical Review Committee of Sir Run Run Hospital, Nanjing Medical University (2019-SR-018).

A total of 540 freshmen of the HHU originating from East (n = 319), Northeast (n = 10), North (n = 85), Northwest (n = 41), Southwest (n = 43), and South (n = 42) of China were enrolled in the present study (Table 1), in which there were 253 males and 287 females aged from 17 to 19. And the precise geographical location of China was shown in figure 1.

Table 1. Demographic characteristics and particular residence of origin of the examined subjects

Region	East	Northeast	North	Northwest	Southwest	South
n	319	10	85	41	43	42
Age	17.9±0.6	18.3±0.7	17.8±0.7	17.9±0.7	17.9±0.6	17.8±0.5
Gender	175/144	6/4	49/36	17/24	22/21	18/24
BMI	20.93±3.1	21.2±3.1	21.2±2.7	20.8±3.4	20.2±3.2	21.9±2.5
Waist	72.9±8.2	73.3±10.3	73.2±8.4	73.4±8.3	71.0±9.0	75.2±7.2
Province	Zhejiang-16	Liaoning-3	Tianjin-7	Shaanxi-10	Yunnan-14	Hunan-17
	Shanghai-2	Jilin-4	Shandong-14	Shanxi-10	Sichuan-17	Guangxi-16
	Jiangxi-18	Heilongjiang-3	Hubei-10	Qinghai-5	Guizhou-12	Guangdong-9
	Jiangsu-248		Henan-31	Ningxia-1
	Fujian-13		Hebei-23	Gansu-15
	Anhui-22

Sample Collection

Examination and sample collection were performed during the first medical screening on admission to the university directly after arrival to HHU using noninvasively collected substrates (urine) in September 2019. Only healthy subjects without chronic diseases were involved in the current investigation to avoid side effects and interactions of diseases on the studied parameters.

Sample Processing

Collection of urine samples (second portion) was performed in the morning using plastic Vacuette^® Urine Collection Cups (Greiner Bio-One International AG, Austria).

Evaluation of dimethoate, BPA, and BaP levels in the urine of examinees was performed using Liquid chromatography-mass spectrometry (LC-MS). The levels of omethoate and 3-hydroxypyrene, metabolites of dimethoate and BaP respectively, and BPA, were examined. The 1 µg/mL standard working solutions of dimethoate, BPA, and BaP were prepared with methanol as solvent. After continuous dilution of 10⁴ times, it became the standard working solution of 100 pg/mL. Take BaP as an example, different concentrations of benzo (a) pyrene standard working solution were prepared. 50 µL of each BaP standard working solution was prepared and injected into the system. The collected urine samples (2 mL) were filtered with 0.22 µM filter membrane, pH was adjusted to 5.4 by adding acetic acid-sodium acetate buffer (0.5 M), then β-glucuronidase/arylsulfatase (10 µL) and vitamin C (5 mg) were added and incubated overnight at room temperature to complete the enzymatic hydrolysis. The samples were extracted, after enzymatic hydrolysis, by solid-phase extraction with SPE column (C18 ENVI 0.25 g). The extract was eluted with methanol (2 mL) and dried with nitrogen. Finally, methanol (100 µL) was used to re-dissolved the analyte to be determined. 50 µL of the analyte to be tested was transferred to a liquid chromatography bottle with a microsyringe, which was especially used for the injection analysis of BaP levels. The detection methods of dimethoate and BPA were consistent with those of BaP[27].

Statistical Analyses

Statistical treatment of raw data was performed using SPSS 26.0 (IBM Corp., Armonk, NY, USA) software. Geometric median (GM) values were used as descriptive statistics for pollutants levels. T-tests were used to compare GMs between categories. Multiple regression analysis was performed to specify the association among the pollutant levels, BMI, and region of origin. All models were adjusted for age and gender variability. The results of the tests were considered significant at p < 0.05.

Urine dimethoate, BPA, BaP were detected in 100% of the recruited people. And the results were presented by volume-based and also by creatinine standardized which was used to eliminate the effect of the time of urine collection, urine concentration, and urine flow rate[28].

Hohai University is a multi-disciplinary comprehensive university located in Jiangsu Province of East China. The freshmen came from all over the country including East, North, South, Northeast, Northwest, and Southwest. We choose East china as the reference category because subjects originating from a distinct part of china carry the patterns of environmental exposure in their domestic region. The obtained data demonstrated that the origin of the students had an important impact on the urine toxins (Table 2). Particularly, the volume-based GM of urine dimethoate, BPA, and BaP concentrations in students from Southwest China was significantly lower than East China by 9.49%, 10.14%, and 8.82%. Likewise, the standardized GM of urine dimethoate, BPA, and BaP concentrations in students from Southwest China was also significantly lower than East China by 10.81%, 11.49%, and 10.26%. Data on other regions were more homogenous.

Table 2. Weighted geometric means of urinary dimethoate, bisphenol A and benzo(a)pyrene, by sex and location group, freshmen aged 17-19 years, China

		Total			Males			Females
Location		Geometric mean	95% confidence interval		Geometric mean	95% confidence interval		Geometric mean	95% confidence interval
Location		Geometric mean	from	to	Geometric mean	from	to	Geometric mean	from	to
Urinary dimethoate
Total	µg/L	9.47	9.28	9.67	10.64	10.34	10.95	8.55^‡	8.35	8.74
µg/g creatinine		10.80	10.58	11.02	11.11	10.76	11.46	10.53	10.26	10.80
Northeast China	µg/L	9.76	8.00	11.91	11.65	7.50	18.11	8.38	7.32	9.58
µg/g creatinine		11.17	9.49	13.15	11.61	7.91	17.03	10.84	8.36	14.04
East China^†	µg/L	9.38	9.13	9.65	10.84	10.38	11.31	8.49	8.24	8.75
µg/g creatinine		10.82	10.52	11.13	11.29	10.78	11.83	10.48	10.12	10.85
North China	µg/L	9.77	9.34	10.22	10.59	9.83	11.40	9.02	8.57	9.50
µg/g creatinine		10.98	10.50	11.49	10.79	10.00	11.63	11.16	10.57	11.79
South China	µg/L	9.96	9.47	10.48	10.48	9.95	11.03	9.14	8.41	9.93
µg/g creatinine		11.15	10.67	11.66	11.04	10.48	11.64	11.31	10.43	12.27
Northwest China	µg/L	9.81	8.92	10.79	10.95	9.71	12.34	8.43	7.44	9.55
µg/g creatinine		10.81	9.77	11.96	11.54	10.09	13.21	9.87	8.40	11.59
Southwest China	µg/L	8.49*	7.82	9.23	9.71	8.45	11.17	7.47	7.01	7.96
µg/g creatinine		9.65*	8.91	10.45	10.26	8.81	11.95	9.10	8.55	9.67
Urinary bisphenol A
Total	µg/L	3.54	3.48	3.61	3.52	3.43	3.62	3.56	3.49	3.65
µg/g creatinine		4.04	3.96	4.12	3.68	3.57	3.79	4.39	4.28	4.50
Northeast China	µg/L	3.68	3.17	4.26	3.68	2.66	5.09	3.65	3.01	4.43
µg/g creatinine		4.21	3.47	4.11	3.67	2.77	4.86	4.70	3.38	6.53
East China^†	µg/L	3.55	3.47	3.63	3.56	3.43	3.70	3.54	3.43	3.64
µg/g creatinine		4.09	3.98	4.21	3.75	3.59	3.91	4.36	4.22	4.52
North China	µg/L	3.65	3.51	3.80	3.54	3.32	3.78	3.75	3.57	3.95
µg/g creatinine		4.11	3.90	4.32	3.57	3.33	3.84	4.64	4.40	4.90
South China	µg/L	3.65	3.47	3.83	3.50	3.29	3.74	3.86	3.59	4.16
µg/g creatinine		4.08	3.87	4.31	3.66	3.44	3.88	4.78	4.45	5.13
Northwest China	µg/L	3.50	3.23	3.78	3.58	3.21	3.98	3.39	2.99	3.85
µg/g creatinine		3.85	3.51	4.23	3.77	3.33	4.26	3.97	3.36	4.69
Southwest China	µg/L	3.19*	2.98	3.40	3.22	2.85	3.63	3.16	2.94	3.39
µg/g creatinine		3.62*	3.36	3.89	3.40	2.96	3.90	3.84	3.61	4.08
Urinary benzo(a)pyrene
Total	ng/L	0.34	0.33	0.35	0.38	0.37	0.39	0.31	0.30	0.32
ng/g creatinine		0.39	0.38	0.40	0.40	0.39	0.41	0.38	0.37	0.39
Northeast China	ng/L	0.35	0.30	0.41	0.39	0.30	0.52	0.32	0.27	0.39
ng/g creatinine		0.40	0.34	0.47	0.39	0.31	0.50	0.41	0.30	0.57
East China^†	ng/L	0.34	0.33	0.35	0.38	0.37	0.39	0.31	0.30	0.32
ng/g creatinine		0.39	0.38	0.40	0.41	0.40	0.42	0.38	0.37	0.39
North China	ng/L	0.35	0.34	0.37	0.38	0.36	0.41	0.33	0.31	0.34
ng/g creatinine		0.40	0.38	0.41	0.39	0.36	0.42	0.40	0.38	0.43
South China	ng/L	0.36	0.34	0.38	0.38	0.35	0.41	0.33	0.31	0.36
ng/g creatinine		0.40	0.38	0.42	0.40	0.37	0.42	0.41	0.39	0.44
Northwest China	ng/L	0.34	0.31	0.38	0.39	0.35	0.43	0.29	0.25	0.33
ng/g creatinine		0.38	0.34	0.42	0.41	0.36	0.46	0.34	0.29	0.40
Southwest China	ng/L	0.31*	0.29	0.33	0.35	0.31	0.39	0.27	0.25	0.29
ng/g creatinine		0.35*	0.33	0.37	0.37	0.32	0.42	0.33	0.31	0.35

Note. † reference category

* signiﬁcantly different from estimate for reference category (p < 0.05)

The volume-based geometric mean (GM) concentration was 9.47 µg/L (Table 3). The GM of urine dimethoate in the female group (8.55 µg/L) was significantly lower than that in the male group (10.64 µg/L). The GM dimethoate concentration rose significantly from 9.12 (µg/L) at the normal BMI (18.5≤BMI≤23.9) to 14.68 (µg/L) at the overweight BMI (BMI>23.9). However, only a moderate change of GM dimethoate concentration was observed between the normal BMI (9.12 µg/L) and the less-weight BMI (BMI<18.5) (8.74 µg/L).

Table 3. Weighted geometric means of urinary dimethoate, bisphenol A and benzo(a)pyrene, by sex and BMI group, freshmen aged 17-19 years, China

		Total			Males			Females
BMI group		Geometric mean	95% confidence interval		Geometric mean	95% confidence interval		Geometric mean	95% confidence interval
BMI group		Geometric mean	from	to	Geometric mean	from	to	Geometric mean	from	to
Urinary dimethoate
Total	µg/L	9.47	9.28	9.67	10.64	10.34	10.95	8.55^‡	8.35	8.74
µg/g creatinine		10.80	10.58	11.02	11.11	10.76	11.46	10.53^‡	10.26	10.80
<18.5	µg/L	8.74	8.28	9.23	9.66	9.02	10.36	7.88	7.39	8.40
µg/g creatinine		10.01	9.48	10.57	10.33	9.66	11.06	9.68	8.86	10.58
18.5 to 23.9^†	µg/L	9.12	8.96	9.29	10.19	9.95	10.42	8.30	8.13	8.47
µg/g creatinine		10.43	10.23	10.62	10.60	10.32	10.89	10.28	10.01	10.55
>23.9	µg/L	14.68*	13.68	15.75	17.49*	16.10	19.00	12.41*	11.68	13.18
µg/g creatinine		16.21*	15.13	17.37	18.16*	16.27	20.27	14.54*	13.63	15.51
Urinary bisphenol A
Total	µg/L	3.54	3.48	3.61	3.52	3.43	3.62	3.56	3.49	3.65
µg/g creatinine		4.04	3.96	4.12	3.68	3.57	3.79	4.39	4.28	4.50
<18.5	µg/L	2.93*	2.79	3.07	2.83	2.64	3.04	3.03	2.84	3.23
µg/g creatinine		3.35	3.15	3.56	3.03	2.83	3.24	3.72	3.41	4.07
18.5 to 23.9^†	µg/L	3.50	3.44	3.55	3.47	3.39	3.55	3.52	3.44	3.60
µg/g creatinine		4.00	3.91	4.08	3.61	3.51	3.71	4.36	4.24	4.47
>23.9	µg/L	4.94*	4.70	5.20	5.13*	4.72	5.57	4.77*	4.49	5.07
µg/g creatinine		5.46*	5.14	5.80	5.32*	4.77	5.94	5.59*	5.24	6.00
Urinary benzo(a)pyrene
Total	ng/L	0.34	0.33	0.35	0.38	0.37	0.39	0.31^‡	0.30	0.32
ng/g creatinine		0.39	0.38	0.40	0.40	0.39	0.41	0.38^‡	0.37	0.39
<18.5	ng/L	0.27*	0.25	0.28	0.29	0.27	0.31	0.25	0.23	0.26
ng/g creatinine		0.31	0.29	0.32	0.31	0.29	0.33	0.30	0.28	0.33
18.5 to 23.9^†	ng/L	0.34	0.33	0.35	0.38	0.37	0.39	0.31	0.30	0.32
ng/g creatinine		0.39	0.38	0.40	0.40	0.39	0.41	0.38	0.37	0.39
>23.9	ng/L	0.45*	0.42	0.48	0.52*	0.48	0.57	0.39	0.37	0.41
ng/g creatinine		0.50*	0.46	0.53	0.54*	0.49	0.61	0.45	0.43	0.48

Note. † reference category

* signiﬁcantly different from estimate for reference category (p < 0.05)

‡ signiﬁcantly different from estimate for males (p < 0.05)

Males with a BMI of more than 23.9 had significantly higher GM dimethoate concentration (17.49 µg/L) compared with the normal BMI (10.19 µg/L). Likewise, females with a BMI of more than 23.9 had significantly higher GM dimethoate concentration (12.41µg/L) compared with the normal BMI (8.3 µg/L).

Standardizing dimethoate with urinary creatinine concentrations resulted in a GM dimethoate concentration of 10.80 µg/g for all recruited people. The standardized GM of dimethoate concentrations in the female group (10.53 µg/g) was significantly lower than that in the male group (11.11 µg/g). The standardized GM of dimethoate concentrations in people with an overweight BMI (16.21 µg/g) was significantly higher than other BMI groups. The only moderate change was observed between the normal BMI (10.43 µg/g) and the BMI less than 18.5 (10.01 µg/g).

The standardized GM of dimethoate concentrations in the overweight male (18.16 µg/g) was significantly higher than that in normal (10.60 µg/g) or less weight male (10.33 µg/g). Likewise, overweight females had significantly higher standardized GM of dimethoate concentration (14.54 µg/g) than normal (10.28 µg/g) or fewer weight females (9.68 µg/g).

The volume-based GM of urine BPA concentration was 3.54 µg/L (Table 3). Interestingly, the GM of urine BPA in the female group (3.56 µg/L) had no significant difference from that in the male group (3.52 µg/L). People with overweight BMI had higher GM of urine BPA concentration (4.94 µg/L) compared with the one with normal (3.50 µg/L) or less weight BMI (2.93 µg/L). Notably, a significant change of GM BPA concentration was also observed between the normal BMI and the less-weight BMI.

Males with overweight BMI had significantly higher GM BPA concentration (5.13 µg/L) compared with the normal BMI (3.47 µg/L) and less weight BMI (2.83 µg/L). Likewise, females with overweight BMI also had significantly higher GM BPA concentration (4.77 µg/L) compared with the normal BMI (3.52 µg/L) and less weight BMI (3.03 µg/L).

Standardizing BPA with urinary creatinine concentrations resulted in a GM BPA concentration of 4.04 µg/g for all recruited people. There was no significant difference found between the male group (3.68 µg/g) and the female group (4.39 µg/g). The standardized GM of BPA concentrations in people with an overweight BMI (5.46 µg/g) was significantly higher than other BMI groups. The only moderate change was observed between the normal BMI (4.00 µg/g) and the less-weight BMI (3.35 µg/g).

The standardized GM of BPA concentrations in the overweight male (5.32 µg/g) was significantly higher than that in normal (3.61 µg/g) or less weight male (3.03 µg/g). Likewise, overweight females had significantly higher standardized GM of BPA concentration (5.59 µg/g) than normal (4.36 µg/g) or fewer weight females (3.72 µg/g).

The volume-based GM of urine BaP concentration was 0.34 ng/L (Table 3). The GM of urine BaP in the female group (0.31 ng/L) was significantly lower than that in the male group (0.38 ng/L). People with overweight BMI had a higher GM of urine BaP concentration (0.45 ng/L) compared with the ones with normal (0.34 ng/L) or less weight BMI (0.27 ng/L). Notably, a significant change of GM BaP concentration was also observed between the normal BMI and the less-weight BMI.

Males with overweight BMI had significantly higher GM BaP concentration (0.52 ng/L) compared with the normal BMI (0.38 ng/L) and less weight BMI (0.29 ng/L). Likewise, females with overweight BMI also had significantly higher GM BaP concentration (0.39 ng/L) compared with the normal BMI (0.31 ng/L) and less weight BMI (0.25 ng/L).

Standardizing BaP with urinary creatinine concentrations resulted in a GM BaP concentration of 0.39 ng/g for all recruited people. A significant difference was found between the male group (0.40 ng/g) and the female group (0.38 ng/g). The standardized GM of BaP concentrations in people with an overweight BMI (0.50 ng/g) was significantly higher than other BMI groups. A significant change was also observed between the normal BMI (0.39 ng/g) and the less-weight BMI (0.31 ng/g).

The standardized GM of BaP concentrations in the overweight male (0.54 ng/g) was significantly higher than that in normal (0.40 ng/g) or less weight male (0.31 ng/g). Likewise, overweight females had significantly higher standardized GM of dimethoate concentration (0.45 ng/g) than normal (0.38 ng/g) or fewer weight females (0.30 ng/g).

Association between urinary toxins levels and BMI, as well as the potential confounding effects of age, gender, and waist, was additionally studied in the regression model (Table 4). Particularly, in this regression model, urinary dimethoate, BPA, and BaP were not associated with age and waist. In turn, gender and BMI were considered as significant predictors of the volume-based concentration of urinary dimethoate, BPA, and BaP. Notably, the male gender was positively associated with the volume-based concentration of urinary dimethoate and BaP while inversely associated with urinary BPA. However, after being standardized by urinary creatinine, the male gender was only inversely associated with urinary BPA. It was also notable that BMI was positively associated with both volume-based and standardized concentrations of urinary dimethoate, BaP, and BPA.

Table 4. Multiple linear regression analysis of the impact of BMI, waist, and gender on the urine toxins in the freshmen

Predictor	Unstandardized						Standardized by creatinine
	Dimethoate		Bisphenol A		Benzo(a)pyrene		Dimethoate		Bisphenol A		Benzo(a)pyrene
	β	p	β	p	β	p	β	p	β	p	β	p
Gender	1.739	<0.001*	-0.183	0.001*	0.063	<0.001*	0.183	0.416	-0.880	<0.001*	0.007	0.394
Age	0.011	0.923	-0.013	0.734	-0.001	0.797	-0.096	0.535	-0.060	0.278	-0.005	0.317
BMI	0.572	<0.001*	0.170	<0.001*	0.016	<0.001*	0.588	<0.001*	0.172	<0.001*	0.016	<0.001*
Waist	0.007	0.648	0.004	0.476	7.743E-5	0.877	0.010	0.647	0.005	0.477	0.000224	0.756

Note. * signiﬁcantly different from estimate for the reference category

In this study, we chose 3 kinds of very common pollutants in the Chinese environment to represent the exposure level of pollutants in Chinese young people aged from 17~19. Besides, the detection does not rely on a blood sample, but urinary samples obtained from non-invasive sources which were easily obtained and low cost. Urine could also better reflecting the changes in human metabolism because the metabolite concentration is higher in urine than in human plasma or serum[29]

The obtained data demonstrate the freshmen of Hohai University originating from distinct geographic regions of China are characterized by increased pollutants exposure levels. Bushnik, T. reported urinary level of BPA in Canada (1.16 µg/L) is almost 1/3 of that in our data (3.54 µg/L)[30]. This may reflect the differences in the situation of BPA pollution between the Chinese and other countries’ environment. Yu., et al reported urinary 1-OHP concentrations increased with increasing concentrations of B[a]P in the industrial area in Lanzhou city[31]. Notably, there is no data report for the urinary level of dimethoate in other countries. So it is meaningful to detect the baseline of these three pollutants to reflect the effects on the human body of the local environment. Furthermore, the male gender shows a significantly higher urinary level of BPA than the female gender in the data from Canada, while no significant sexual difference of BPA level was observed in our data. This may reflect the differences in pharmacokinetic factors between genders and races, the relevance of which is not currently known[32].

Despite no differences in urinary BPA between genders in our data, the male gender exhibited a significantly higher level of urinary dimethoate and BaP than the female gender (Table 3). Moreover, gender was considered as a significant predictor of the urinary level of dimethoate and BaP in the regression model. This may reflect the differences in the lifestyle between males and females.

Association of BMI and the urinary level of dimethoate, BaP, and BPA was additionally studied in regression models. In particular, BMI could be considered as a significant predictor of the urinary level of these three pollutants no matter whether be standardized by urinary creatinine or not (Table 4). Since most persistent organic pollutants (POPs) are lipophilicity[33], it has been widely studied that POPs could be stored in the adipose tissue[33-35]. Moreover, the accumulated POPs could also increase the risks of obesity and diabetes by inducing adipogenesis[36, 37] and inhibiting glucose uptake[38]. This reflects that adipose tissue can act as a storage for most pollutants in our bodies. The stored pollutants in the adipose tissue can further enhance adipogenesis and insulin resistance. Together with our data, the increasing BMI and obesity can be a risk factor for higher pollutants accumulation in our body which could further act as the obesogens.

Besides the index of BMI, we found that the students from Southwest China had a significantly lower level of all three pollutants compared with East China which was considered as the control group (Table 2). Interestingly, there is no significant difference in BMI between students from Southwest China and East China. This reflects that the living environment and lifestyle may determine this difference.[39]

Although there are very few reports to study the difference among various provinces in China, it has been reported that air pollution in North China is much worse than in South China[40]. This may partially explain our data and indicates that the living environment can determine the level of accumulated pollutants in our bodies. To investigate the relationship of the accumulated pollutants in our body and our health, further researches are needed to study the detailed differences in the living environment and lifestyle between people from Southwest China and other geographic regions in China. The baseline information of dimethoate, BaP, and BPA level will improve public health awareness and have important implications for health policy formulation.

BaP: Benzo(a)pyrene; BPA: Bisphenol A; GM: Geometric means; BMI: Body Mass Index; PAHs: Polycyclic aromatic hydrocarbons; HHU: Hohai University; LC-MS: Liquid chromatography-mass spectrometry

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Not applicable.

Availability of data and materials

All data generated or analysed during this study are included in this published article.

Competing interests

The authors declare that they have no competing interests.

Funding

This work was supported by the Key R&D Program of Jiangsu Province (BE2017708), the Chinese National Science Foundation (32071145, 31771572), the Nature Science Foundation of Jiangsu Province (BK20191356), the Six talent peaks project in Jiangsu Province (yy-014), Qin Lan Project of Jiangsu Province (KY520R202025), the Science and Technology Development Fund of Nanjing Medical University - General Project (NMUB2019079), the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (20KJB180004), the Chinese National Science Foundation (81700710), the joint project of Sir Run Run Hospital, Nanjing Medical University and China Exposomics Institute (CEI) Precision Medicine Co. Ltd (YFHX2020-001) and the joint project of Hohai University and China Exposomics Institute (CEI) Precision Medicine Co. Ltd (1094/CZ819129916).

Authors' contributions

YJX, CJL, JW, NS, and BX contributed equally to the design of the study and the direction of its implementation, including supervision of the field activities, quality assurance, and control. FZ and XLX supervised the field activities. YJX, NWZ, and JY were responsible for sample collection. YJX, HLG, HL, NS, and BX helped conduct the literature review and prepare the Materials and methods and the Discussion sections of the text. QC, FRZ, AQW, BM, YJD, and NS designed the study’s analytic strategy and conducted the data analysis. All authors read and approved the final manuscript.

Author details

¹Hohai University, Nanjing 210098, China. ²Core Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing 211166, China. ³General surgery department, Sir Run Run Hospital, Nanjing Medical University, Nanjing 211166, China. ⁴Department of Urology, Sir Run Run Hospital, Nanjing Medical University, 109 Longmian Road, Jiangning, 211100 Nanjing, Jiangsu, China. ⁵Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing 210029, China. ⁶Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210028, China. ⁷China Exposomics Institute (CEI) Precision Medicine Co. Ltd, Shanghai 200120, China. ⁸Medical School of Nanjing University, Nanjing, 210093, China. ⁹State Key Laboratory of Pharmaceutical Biotechnology, Medical School of Nanjing University & Model Animal Research Center, Nanjing University, Nanjing 210093, China.

Li AM: Ecological determinants of health: food and environment on human health. Environ Sci Pollut Res Int 2017, 24(10):9002–9015.
Yong CQY, Valiyaveetill S, Tang BL: Toxicity of Microplastics and Nanoplastics in Mammalian Systems. Int J Environ Res Public Health 2020, 17(5).
Davis AP, Murphy CG, Saraceni-Richards CA, Rosenstein MC, Wiegers TC, Mattingly CJ: Comparative Toxicogenomics Database: a knowledgebase and discovery tool for chemical-gene-disease networks. Nucleic Acids Res 2009, 37(Database issue):D786-792.
Hu Y, Ji L, Zhang Y, Shi R, Han W, Tse LA, Pan R, Wang Y, Ding G, Xu J et al: Organophosphate and Pyrethroid Pesticide Exposures Measured before Conception and Associations with Time to Pregnancy in Chinese Couples Enrolled in the Shanghai Birth Cohort. Environ Health Perspect 2018, 126(7):077001.
Xu X, Li L, Huang X, Lin H, Liu G, Xu D, Jiang J: Survey of Four Groups of Cumulative Pesticide Residues in 12 Vegetables in 15 Provinces in China. J Food Prot 2018, 81(3):377–385.
Zhao X, Zhao C, Du X, Dong D: Detecting and Mapping Harmful Chemicals in Fruit and Vegetables Using Nanoparticle-Enhanced Laser-Induced Breakdown Spectroscopy. Sci Rep 2019, 9(1):906.
Damalas CA, Eleftherohorinos IG: Pesticide exposure, safety issues, and risk assessment indicators. Int J Environ Res Public Health 2011, 8(5):1402–1419.
Van Scoy A, Pennell A, Zhang X: Environmental Fate and Toxicology of Dimethoate. Rev Environ Contam Toxicol 2016, 237:53–70.
Reuber MD: Carcinogenicity of dimethoate. Environ Res 1984, 34(2):193–211.
Pardo LA, Beane Freeman LE, Lerro CC, Andreotti G, Hofmann JN, Parks CG, Sandler DP, Lubin JH, Blair A, Koutros S: Pesticide exposure and risk of aggressive prostate cancer among private pesticide applicators. Environ Health 2020, 19(1):30.
Guo Q, Zhou M, Liu N, Wang Y: Spatial Effects of Environmental Regulation and Green Credits on Green Technology Innovation Under Low-Carbon Economy Background Conditions. Int J Environ Res Public Health 2019, 16(17).
Bansal V, Kim KH: Review of PAH contamination in food products and their health hazards. Environ Int 2015, 84:26–38.
Forsberg ND, Stone D, Harding A, Harper B, Harris S, Matzke MM, Cardenas A, Waters KM, Anderson KA: Effect of Native American fish smoking methods on dietary exposure to polycyclic aromatic hydrocarbons and possible risks to human health. J Agric Food Chem 2012, 60(27):6899–6906.
Upadhyaya P, Hochalter JB, Balbo S, McIntee EJ, Hecht SS: Preferential glutathione conjugation of a reverse diol epoxide compared with a bay region diol epoxide of benzo[a]pyrene in human hepatocytes. Drug Metab Dispos 2010, 38(9):1397–1402.
Baird WM, Mahadevan B: The uses of carcinogen-DNA adduct measurement in establishing mechanisms of mutagenesis and in chemoprevention. Mutat Res 2004, 547(1–2):1–4.
Cavalieri EL, Rogan EG: Central role of radical cations in metabolic activation of polycyclic aromatic hydrocarbons. Xenobiotica 1995, 25(7):677–688.
Culp SJ, Gaylor DW, Sheldon WG, Goldstein LS, Beland FA: A comparison of the tumors induced by coal tar and benzo[a]pyrene in a 2-year bioassay. Carcinogenesis 1998, 19(1):117–124.
Ramadan M, Sherman M, Jaimes R, 3rd, Chaluvadi A, Swift L, Posnack NG: Disruption of neonatal cardiomyocyte physiology following exposure to bisphenol-a. Sci Rep 2018, 8(1):7356.
Wetherill YB, Akingbemi BT, Kanno J, McLachlan JA, Nadal A, Sonnenschein C, Watson CS, Zoeller RT, Belcher SM: In vitro molecular mechanisms of bisphenol A action. Reprod Toxicol 2007, 24(2):178–198.
Li D, Zhou Z, Qing D, He Y, Wu T, Miao M, Wang J, Weng X, Ferber JR, Herrinton LJ et al: Occupational exposure to bisphenol-A (BPA) and the risk of self-reported male sexual dysfunction. Hum Reprod 2010, 25(2):519–527.
Meeker JD, Ehrlich S, Toth TL, Wright DL, Calafat AM, Trisini AT, Ye X, Hauser R: Semen quality and sperm DNA damage in relation to urinary bisphenol A among men from an infertility clinic. Reprod Toxicol 2010, 30(4):532–539.
Rochester JR: Bisphenol A and human health: a review of the literature. Reprod Toxicol 2013, 42:132–155.
Owczarek K, Kudlak B, Simeonov V, Mazerska Z, Namiesnik J: Binary Mixtures of Selected Bisphenols in the Environment: Their Toxicity in Relationship to Individual Constituents. Molecules 2018, 23(12).
Zeng HL, Li H, Lu J, Guan Q, Cheng L: Assessment of 12 Metals and Metalloids in Blood of General Populations Living in Wuhan of China by ICP-MS. Biol Trace Elem Res 2019, 189(2):344–353.
Zeng HL, Liu CW, Lu J, Wang X, Cheng L: Analysis of urinary trace element levels in general population of Wuhan in central China. Environ Sci Pollut Res Int 2019, 26(27):27823–27831.
Tinkov AA, Skalnaya MG, Aaseth J, Ajsuvakova OP, Aschner M, Skalny AV: Aluminium levels in hair and urine are associated with overweight and obesity in a non-occupationally exposed population. J Trace Elem Med Biol 2019, 56:139–145.
Jacob P, 3rd, Wilson M, Benowitz NL: Determination of phenolic metabolites of polycyclic aromatic hydrocarbons in human urine as their pentafluorobenzyl ether derivatives using liquid chromatography-tandem mass spectrometry. Anal Chem 2007, 79(2):587–598.
Tang KW, Toh QC, Teo BW: Normalisation of urinary biomarkers to creatinine for clinical practice and research–when and why. Singapore Med J 2015, 56(1):7–10.
Ahn JK, Kim J, Hwang J, Song J, Kim KH, Cha HS: Urinary Metabolomic Profiling to Identify Potential Biomarkers for the Diagnosis of Behcet's Disease by Gas Chromatography/Time-of-Flight-Mass Spectrometry. Int J Mol Sci 2017, 18(11).
Bushnik T, Haines D, Levallois P, Levesque J, Van Oostdam J, Viau C: Lead and bisphenol A concentrations in the Canadian population. Health Rep 2010, 21(3):7–18.
Yu Y, Wang Q, Li L, Liu Z, Sun P, Zhang Y, Lin H, Xiang M, Li H, Lin B: Particle-Associated Ambient Benzo[a]pyrene and Levels of Urinary 1-Hydroxypyrene in a Non-occupationally Exposed Population of Adults and Children in Lanzhou, China. Bull Environ Contam Toxicol 2016, 96(3):303–308.
Calafat AM, Ye X, Wong LY, Reidy JA, Needham LL: Exposure of the U.S. population to bisphenol A and 4-tertiary-octylphenol: 2003–2004. Environ Health Perspect 2008, 116(1):39–44.
Kohlmeier L, Kohlmeier M: Adipose tissue as a medium for epidemiologic exposure assessment. Environ Health Perspect 1995, 103 Suppl 3:99–106.
Petreas M, Smith D, Hurley S, Jeffrey SS, Gilliss D, Reynolds P: Distribution of persistent, lipid-soluble chemicals in breast and abdominal adipose tissues: lessons learned from a breast cancer study. Cancer Epidemiol Biomarkers Prev 2004, 13(3):416–424.
Levitt DG: Quantitative relationship between the octanol/water partition coefficient and the diffusion limitation of the exchange between adipose and blood. BMC Clin Pharmacol 2010, 10:1.
Hurst CH, Waxman DJ: Activation of PPARalpha and PPARgamma by environmental phthalate monoesters. Toxicol Sci 2003, 74(2):297–308.
Feige JN, Gelman L, Rossi D, Zoete V, Metivier R, Tudor C, Anghel SI, Grosdidier A, Lathion C, Engelborghs Y et al: The endocrine disruptor monoethyl-hexyl-phthalate is a selective peroxisome proliferator-activated receptor gamma modulator that promotes adipogenesis. J Biol Chem 2007, 282(26):19152–19166.
Ruzzin J, Petersen R, Meugnier E, Madsen L, Lock EJ, Lillefosse H, Ma T, Pesenti S, Sonne SB, Marstrand TT et al: Persistent organic pollutant exposure leads to insulin resistance syndrome. Environ Health Perspect 2010, 118(4):465–471.
Liang D, Wang YQ, Wang YJ, Ma C: National air pollution distribution in China and related geographic, gaseous pollutant, and socio-economic factors. Environ Pollut 2019, 250:998–1009.
Song C, Wu L, Xie Y, He J, Chen X, Wang T, Lin Y, Jin T, Wang A, Liu Y et al: Air pollution in China: Status and spatiotemporal variations. Environ Pollut 2017, 227:334–347.

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Urinary Level of Dimethoate, Bisphenol a and Benzo[a]pyrene in the First-year Students of Hohai University From Different Geographical Regions

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