Association between Arsenic and Generalized Anxiety Disorder: A Cross-Sectional Study

Research Article | DOI: https://doi.org/10.31579/2642-9756/054

Association between Arsenic and Generalized Anxiety Disorder: A Cross-Sectional Study

  • Lei Zhang 1#
  • Minzhi Cao 2#
  • Linnan Guo 1
  • Li Wang 3
  • Min Zhang 3
  • Jiajia Qian 3
  • Scottie Bussell 4
  • Na Wang 1*
  • Suhua Wang 3*

1# School of Public Health, Guilin Medical University, Guilin530021, Guangxi, China
2# Bayannaoer Center for Disease Control and Prevention, Bayannaoer 015000, Inner Mongolia China
3 School of Public Health, Baotou Medical College, Baotou014040, Inner Mongolia, China
4 Department of Health and Human Services, Parker Indian Hospital, Parker, Arizona, USA.

*Corresponding Author: Na Wang, School of Public Health, Guilin Medical University, Guilin 530021, Guangxi,China. Suhua Wang, School of Public Health, Baotou Medical College, Baotou014040, Inner Mongolia, China.

Citation: Na Wang, Lei Zhang, Minzhi Cao, Suhua Wang, Li Wang et all (2021) Association Between Arsenic And Generalized Anxiety Disorder: A Cross-Sectional Study. J.Women Health Care and Issues, 4(4); DOI:10.31579/2642-9756/054

Copyright: © 2021 Na Wang, This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: 12 April 2021 | Accepted: 19 April 2021 | Published: 27 April 2021

Keywords: arsenic; generalized anxiety disorder

Abstract

Aim: In some regionsof Bayannaoer arsenicconcentration in well drinking water is higherthan the international standard of 10 μg/L. The purpose of this study is to evaluate the impact of exposures to arsenic in drinking water on generalized anxiety disorder (GAD).

Materials and Methods: Asurvey was conducted in2016 among villagers in Hangjinhou County,Bayannaoer City, Inner Mongolia. A questionnaire was used to inquire about GAD, arsenic related neurological symptoms. Arsenic concentration in the water was measured and arsenicosis prevalence was assessed. Multinomial logistic regression and ordinal logistic regression were performed to evaluate the association of abnormal arsenic levels on increased GAD symptoms.

Results: 446 participants were enrolled. Subjectswith exposure to water arseniclevels>10 μg/L were significantly more likely to have mild GAD than controls (adjusted odds ratio [AOR] =2.3, 95% confidence interval [CI], 1.1-4.8). Participants who were diagnosed with arsenicosis were more likely to report mild anxiety than minimal anxiety compared to those who did not (AOR=2.3, 95% CI, 1.3-4.1). Survey respondents with palpitations, forgetfulness, headaches, dizziness, decreased taste, decreased hearing,loss of touch,abnormal warm and cold sensation, blurred vision, numbness and tingling were more likely to report mild, moderate and severe anxiety.

Conclusions: Arsenic exposure was associated with a higher risk of GAD. Screening for arsenic exposure should be incorporated into the evaluation of GAD, in areas where arsenic in drinking water is known to be abnormal.

Introduction

Anxiety disorders are common psychiatric disordersamong various people [1-4]. Generalized anxiety disorder (GAD) is the most common anxiety disorder[5]. People with GAD diagnostic often show excessive and persistent inexplicable tensions and fears with a lack of specific objects and specific content [6].

GAD has serious economic and social burdens in China. In the urban China, the prevalence of GAD was 5.3% [7]. Individuals with GAD are more likely to have suicidal ideation and attempt suicide than persons with other anxiety disorders [8, 9].

Arsenic exists in a high level in groundwater across Inner Mongolia Provincein northern China,including Bayannao'er, a prefecture-level city

on the Hetao Plain. Bayannao'er is a major endemic area with high concentration of arsenic in groundwater (543 villages with concentration>50 μg/L)[10]. People are exposedthrough drinking water[10]. Arsenic related adverse health effects in this region are well known [10-13]. In 1995, 81% of all arsenicosis cases, mainly skin hyperkeratosis, depigmentation, hyperpigmentation and skin cancer, in Inner Mongolia were from Bayannaoer and there was a dose-response between the prevalence of arsenicism and concentration of arsenic in drinkingwater [10].

As arsenic can cross the blood-brain barrier and accumulate in nerve tissues, a study have reported that drinking water arsenic exposurecauses a varietyof neuropsychiatric symptoms, including hearing loss,taste loss, blurred vision, limb numbness and tingling[14]. Studies have found that arsenic exposure is associated with anxietydisorders [15-18]. Moreover, arsenic is neurotoxic [19, 20]. Higher levels of arsenic in drinkingwater are associated with a higherrate of suicide,which may be correlated with arsenic related anxiety [21]. A study reported that 4.61% of arsenicosis patients had mixed anxiety and depressive disorders and 0.26% had GAD[15].

Since 2001, both centraland local governments have invested in driving- water improvement programs to reduce fluorine and arsenic levels in drinking water in Inner Mongolia. Local residents were supplied with water that reduced arsenic levels by centralized water wells. Despite efforts by local governments in Bayannaoer, at the end of 2011, arsenic concentration in well drinking water was higher than the international standardof 10 μg/L in some regions.For example, local surveillance data showedwater arsenic level >80 μg/L for four consecutive years in Defengvillage, Hangjinhou county. Public health officials and mental health professions are concerned that this levelof arsenic in drinking water may be contributing to excess anxietydisorder prevalence.

We conducted a cross-sectional study in Hangjinhou County to investigate the prevalence of GAD among local residents and assess the association between arsenic, such as arsenicin drinking water,arsenicosis and arsenic relatedneurological symptoms, and GAD.

Materials and Methods

Study Design

In December 2016, a cross-sectional survey was conducted among residents in Hangjinhou County. According to whether arsenic in drinking water>10 ug/L, all the villages were divided into two layers, then, villages were randomly selected from these two layers. Four villages (Defeng, Gaofeng, Chunguang and Zhongnanqu in Hangjinghou County were selected. Defeng, Gaofeng and Chunguang were covered by two improvement wells with water arsenic concentration>10 μg/L. Zhongnanqu was supplied by one improvement well with water arsenic concentration <10>

Data Collection

Personal interviews were conducted by trained interviewers to collectdemographic data including age, gender, ethnicity, education, marital status, occupation, familyincome in the past 12 months, durationof living in study sites, out-migration in the past 12 months, medical history, arsenic related neurological symptoms (e.g. palpitations, forgetfulness, headaches and dizziness, decreased taste, decreased hearing loss, loss of touch, abnormal warm and cold sensation, blurred vision, numbness and tingling)and GAD symptoms in the last 2 weeks.

GAD was measured using a 7-item scale Generalized Anxiety Disorder(GAD-7) (Cronbach’s alpha=0.89 in our study). The GAD-7 scale has seven items on the symptoms of GAD over the last 2 weeks.A sum score is calculated by adding the answers of all items on a four-point Likert scale (0–3) ranging from 0 to 21. The scores of 0-4, 5-9, 10-14 and 15 or more are categorized as minimal, mild, moderate and severe anxiety, respectively [22].

Arsenicosis was diagnosed by physicians familiar with patients with thisdisorder. Diagnostic criteria for endemic arsenic poisoning (WS/T 211- 2005) included: living in an endemic arsenic area, having a history of excessivearsenic exposure, and having keratosisof the metacarpophalangeal skin [23].

Since the water improvement project was completed in 2011 in all of the4 study villages, residents around the wells shared the same drinking water source. Participants in our study lived near three wells thus water samples from three improvement wells were collected and tested for arsenicconcentration. Water sampleswere collected with sterile polyethylene bottles and arseniclevels were measuredusing a spectrophotometer with a detection limit of 10 μg/L (T6, Puxi Co. Beijing,China).

Statistical Analysis

Epidata 3.1 software was used for data entry and management. SAS version9.2 (SAS Institute, Cary, NC) was used for statistical analysis. The primary dependent variable was GAD, which was classified into four categories as described above. The main predictor of GAD were arsenic concentration in drinking water, arsenicosis and as well as arsenicrelated neurological symptoms.Simple descriptive statistics for the main outcome and predictors were calculated. Multinomial logistic regressions and ordinal logistic regression were used. ORs were calculated with age group and genderadjusted modelsand fully adjustedmodels that includedage group, gender, ethnic, education, marital status, occupation, family income in the last 12 months, duration of living in study villages, ever out-migration in the past 12 months, and medical history.

Results

Of 459 residents from 4 villages, 446 (97%) were enrolled in the study. Age ranged from 18 to 86 years old. The majority of participants were farmers (94.2%), 18-60 (65.7%) years old, female (59.0%), Han ethnic (98.4%),married (91.3%),and had an elementary schooleducation or less(55.2%). Most participants had lived in the study villages for 20 years or more (94.8%), had a familyincome of more than 15,000 RMB in the last 12 months (60.5%), did not leave the villages in the past 12 months (88.4%), and had no comorbidities (56.0%).

Of all participants, 71.8% (320/446) had minimal anxiety,18.6% (83/446) had mild anxiety, 4.9% (22/446) had moderate anxiety, and 4.7% (21/446)had severe anxiety. Compared to minimal anxiety, mild, moderate and severe anxiety were significantly (p<0>

*measured by GAD-7; RMB: Renmenbi, approximately US $0.15.Table 1. Characteristics of participants, Bayannaoer City in Northern China, 2016 (N=446)

Among 446 participants, 50.4% (225) drank water with arsenic contaminant level at 80 μg/L, 28.2% (126) drank water with arsenic level at 20 μg/L, and a total of 78.7% (351) drank well water with arsenic contaminant level >10 μg/L, and 21.3% (95) drank water with <10>

24.4% (109) were diagnosed with arsenicosis. Some of them had arsenic related neurological symptoms, such as palpitations (35.2%), forgetfulness(61.2%), headaches and dizziness(50.0%), decreased taste(10.3%), decreased hearing loss(27.1%), loss of touch(2.7%), abnormal warm and cold sensation(12.6%), blurred vision(50.7%), numbness and tingling(30.3%).

Compared to minimal anxiety, mild anxiety was significantly (p<0>

*measured by GAD-7.Table 2. Generalized anxiety disorder prevalence by arsenic exposure and arsenic related neurological symptoms among 446 participants (n/%)

Participants who drinking water with arsenic concentration over 10 μg/L were more likely to report mild anxiety than minimal anxiety compared to those with arsenic within 10 μg/L according to the multinomial logistic regressions, in the age group and gender adjusted models (AOR=2.4, 95% CI, 1.2-4.8) and fully adjusted models (AOR=2.3, 95% CI, 1.1-4.8). Participants who were diagnosed with arsenicosis were more likely to report mild anxiety than minimal anxiety compared to those did not in the age group and gender-adjusted models (AOR=2.4, 95% CI, 1.4-4.1) and fully adjusted models (AOR=2.3, 95% CI, 1.3-4.1). Palpitations (AOR=3.0, 95% CI, 2.0-4.6), (AOR=2.7, 95% CI, 1.6-4.0), forgetfulness (AOR=2.3, 95% CI, 1.4-3.6), (AOR=2.0, 95% CI, 1.2-3.2) , headaches and dizziness (AOR=2.5, 95% CI, 1.6-3.9), (AOR=22, 95% CI, 1.4-3.5), decreased taste (AOR=3.5, 95% CI, 1.9-6.3), (AOR=3.2, 95% CI,1.7-6.0), decreased hearing loss (AOR=2.9, 95% CI, 1. 9-4.6), (AOR=2.8, 95% CI, 1.7-4.5), loss of touch (AOR=11.0, 95% CI, 3.8-31.9), (AOR=7.9, 95% CI, 2.5-25.0), abnormal warm and cold sensation (AOR=5.8, 95% CI, 3.3-9.9), (AOR=5.6, 95% CI, 3.1-9.9) , blurred vision (AOR=1.9, 95% CI, 1.3-2.9), (AOR=2.1, 95% CI, 1.3-3.2), numbness and tingling (AOR=2.1, 95% CI, 1.4-3.2), (AOR=1.7, 95% CI, 1.1-2.7) were more likely to report mild, moderate and severe anxiety in the age group and gender adjusted models and fully adjusted models of multiple ordinal logistic regression. (Table 3)

* The variable was significant at 0.05 level; aadjusted for age group and gender; bAdjusted for age group, gender, ethnic, education, marital status, occupation, family income in the last 12 months, duration of living in study villages, ever out-migration in the past 12 months, and medical history.Table 3 Association between arsenic and GAD (N=446)

Discussion

In our study, the rate of moderate and severe GAD was 10.2% and 7.4% among a sample of people living in an arsenic endemic zone and control regions.Both were higherthan urban Chineseof 5.3% [7] , the higher rate of this rural area may be contributed by financial pressureand health careand especially arsenic exposure.

Our study showed that there was a statistically significant association between mild GAD with arsenicosis and exposure to a moderate level of arsenic in drinking water (arsenic>10 μg/L). A study from India revealed that a higher prevalence of anxiety was reported in arsenic endemiczones (arsenic in groundwater, 10-50 μg/L) than in control regions (≤10 μg/L) [17]. A study reported that 4.61% of arsenicosis patients had mixed anxiety and depressive disorders and 0.26% had GAD[15], but the study did not have non-arsenicosis controls.

To our knowledge, there are few studies assessingthe relationship between GAD and moderate level of arsenic centration in drinking water and arsenicosis. After the water-improvement campaign was completed in 2011 across all arsenic endemic regions in Bayannaoer, residents had access to water with lower arsenic levels. So the level of arsenic in the improvement wells’ water that they were using could not reflect the level of arsenic intake. In consideration of that, we measured arsenicosis to reflect arsenic exposure. Arsenicosis is caused by long term (6 months plus) ingestion of arsenic abovea safe dose, characterized by skin lesionsand possible involvement of internal organs[24]. Arsenicosis reflects a cumulative exposure of arsenic. Our study also measured arsenic related neurological symptoms to assess the relationship between arsenic and GAD comprehensively.

There are several limitations to our study. First, we could not prove the relationship betweenexposures to arsenicand GAD using this cross-sectional design. Second, since the late 1970s, deep artesian wells were popular, which were often contaminated by arsenic in Bayanaoer [25], some people may be exposed to arsenic for nearly 50 years. We were unable to estimate the total amount of arsenic that study participants had ingested because the water quality was improved and the arsenic in drinking water was reduced. Future studies could measure the arsenic level of the deep artesian wells and drinking year history. Third, due to the measureof self-reporting of GAD, prevalence might be underreported in the questionnaire interview. However, we selected villages randomly from two layers with water arsenic>10 μg/L or <10>

Conclusion

Mild GAD was statistically significantly associated with arsenicosis andexposure to moderate level of arsenic in drinking water. People with arsenic exposure, especially in endemic areas; should be asked routinely about GAD screening.

Conflict Of Interest Statement

The authors declare no conflict of interest.

Acknowledgements

This work was funded in part by National Natural Science Foundation of China, Grantnumber 81760616 and number 81660532.

References

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